John McEwen was born on 29 March 1900 at Chiltern in Victoria, to pharmacist David McEwen and Amy (Porter) McEwen. His mother died after the birth of their second child in 1901, and his father died in 1907. McEwen and his younger sister were raised by their grandmother, Ellen Porter, who ran a boarding house. They lived first at Wangaratta and then moved to Dandenong in 1912. At the age of 13 McEwen left school and worked at local wholesale pharmaceutical supplier Rocke, Tompsitt & Co. In 1914, the family moved to the Melbourne suburb of Balwyn, where McEwen studied at night school.

After two years of classes at Hassett's Business College, he qualified for entry to the Commonwealth Public Service. At the age of 16 he started work at the Crown Solicitor's Office in Melbourne, under Frederick Whitlam, the father of Gough Whitlam. McEwen had hoped to enroll at the Royal Military College at Duntroon in Canberra, but instead applied for enlistment in the 1st Australian Imperial Force when he turned 18 and was called up on 9 August 1918. After his discharge he went to work as a farmhand, but his enlistment qualified him for a loan to buy a farm under the "soldier-settler" scheme. He applied for a 35-hectare block at Tongala in Victoria's Goulburn Valley. To raise capital he took labouring jobs, including one on the Melbourne wharves. He joined the Victorian Farmers Union in 1919, one of the most influential of the primary producers groups that founded the Country Party the following year. On 21 September 1921 John McEwen and Anne McLeod were married at Ballavoca, Tongala. In 1924 the couple sold their 1200 hectare dairy farm for £1000 to buy a larger property they named 'Chilgala'. They developed it first as a sheep station and later changed to beef cattle. In 1923-24 McEwen was the first chairman of the local Stanhope Dairy Cooperative.

In 1932 McEwen stood unsuccessfully as Country Party candidate for the seat of Waranga in the Victorian parliament. The State party then endorsed him for the federal seat of Echuca. Country Party parliamentary leader Earle Page was then in dispute with the Victorian Country Party, and at the 1934 federal election Page campaigned for an 'Independent Country Party' candidate against McEwen. McEwen won the electorate and took his seat in the 14th parliament. He joined the parliamentary Country Party led by Page, and was thus also in dispute with his own State party.

When Joseph Lyons won government in 1932, the United Australia Party was able to govern alone. Lyons attempted to continue this in the 14th parliament. On 23 October 1934, the first sitting day, the Country Party defeated the government's motion to adjourn until the day after the Melbourne Cup. The Duke of Gloucester was visiting Australia for Victoria's centenary and Cup week in Melbourne was a special event - much to the inconvenience of parliamentarians sitting in the new Parliament House in Canberra. Lyons immediately responded to the Country Party's demonstration of the government's reliance on their numbers, and negotiated a coalition government. On 9 November a new Cabinet was sworn in, including four Country Party members - Earle Page, Thomas Paterson, Harold Thorby and James Hunter. Country Party leader Earle Page resumed the role of deputy Prime Minister he had held from 1923 to 1929 under Prime Minister SM Bruce. In 1935 and 1936 McEwen was a member of the parliament's Bankruptcy Legislation Committee, and spoke on a proposal for a royal commission into the monetary and banking system.

At the federal election in October 1937, McEwen was returned for the electoral division of Indi, his Echuca seat having been abolished in 1937. The coalition ministry was reshuffled after the election, and five Country Party ministers were sworn in on 29 November 1937. McEwen replaced Thomas Paterson as Minister for the Interior, with responsibility for Commonwealth public works, railways, immigration, territories, electoral administration, mining and oil exploration. In 1938 McEwen made a 6-week 'safari' through the Northern Territory which, with the Federal Capital Territory, was included in his portfolio.

The Victorian Country Party remained at odds with its federal leadership, and had ruled that no member could join a coalition government. McEwen was expelled by his party at a tense branch meeting at Benalla in Victoria on 28 January 1938 and was not permitted to speak during the expulsion debate. The Country Party had its first experience of holding the top post formally when Earle Page became 'caretaker' Prime Minister after the death of Joseph Lyons on 7 April 1939. On 26 April, after Robert Menzies was elected leader of the United Australia Party, Page refused to serve in coalition with him and all five Country Party ministers went with him. Menzies formed a ministry composed only of United Australia Party members. Page's attack on Menzies in parliament had undermined his leadership of his own party and on 13 September 1939 he resigned. McEwen contested the leadership against Archie Cameron, losing by two votes. Described as a stubborn and even belligerent man, Cameron was an unlikely leader. In 1938 he had become the first minister suspended from the federal parliament for his obstinate refusal to obey the Speaker's ruling to withdraw his rural, but hardly rude, reference to Independent Alex Wilson as a "clean-skin".

After Richard Casey's seat of Corio was lost to Labor in a by-election in March 1940, Robert Menzies and Archie Cameron negotiated a coalition which would include five Country Party ministers, but exclude Earle Page. On 14 March 1940 the new Country Party ministers were sworn in - McEwen as Minister for External Affairs, Archie Cameron as Minister for Commerce and Minister for the Navy, Harold Thorby as Postmaster-General and Minister for Health, and Horace Nock and Arthur Fadden as ministers without portfolio. Five months later, after three of Menzies' ministers were killed when their aeroplane crashed near Canberra, Arthur Fadden became Minister for Air and Minister for Civil Aviation.

In October 1940 Archie Cameron resigned as Country Party leader and both Earle Page and John McEwen stood for the leadership and were tied when the votes were counted. To resolve the deadlock temporarily, deputy leader Arthur Fadden was made acting leader. The Menzies-Fadden coalition ministry included five Country Party ministers. On 28 October 1940 Arthur Fadden was sworn in as Treasurer, John McEwen as Minister for Air and Minister for Civil Aviation, Earle Page as Minister for Commerce, and HL Anthony and Joseph Abbott as ministers without portfolio. On 26 June 1941, Anthony became Minister for Transport and Abbott Minister for Home Security - giving the Country Party two of the five new wartime portfolios established by Menzies.

The War Cabinet had met for the first time on 27 September 1939, but in 1940 the government established an all-party Advisory War Council under the National Security regulations to involve the Opposition and promote national unity for the war effort. The members were Robert Menzies, WM Hughes, Percy Spender and Arthur Fadden from the coalition, and John Curtin, Frank Forde, Jack Beasley and Norman Makin from the Labor Opposition. As Minister for Air, McEwen became a member of the Advisory War Council and attended his first meeting on 7 November 1940.

McEwen was Minister for Air from October 1940 to October 1941. During this time Australia played a major role in the Empire Air Training Scheme and the Women's Auxiliary Australian Air Force was established. McEwen and Norman Makin were strong opponents of the enlistment of women and the Auxiliary was only established through Burnett's determined arguments. He insisted that the numbers of telegraphist's and radio operators essential to the Air Force could only be achieved if the hundreds of Australian women with these skills could be recruited. The proposal was not approved until 4 February 1941. Despite Norman Makin's case for equal pay if the proposal went ahead, the Council included the condition that the women would receive two-thirds of the wages of men in the same jobs.

From January to May 1941 Arthur Fadden was acting Prime Minister while Robert Menzies was in London. The Country Party confirmed Fadden as leader on 12 March 1941. When the United Australia Party removed Robert Menzies as leader on 28 August, the coalition parties voted Arthur Fadden to lead the coalition. The Governor-General commissioned Fadden as Prime Minister on 29 August 1941, but Fadden's term was brief. On 3 October 1941 the two Independents, Alex Wilson and Arthur Coles, voted with the Opposition and the government fell. The Country Party and the United Australia Party remained on the Opposition benches for eight years. During the war years, Curtin maintained the all-party bodies involved with the war effort and retained United Australia Party and Country Party members on the Advisory War Council. McEwen was also a member of the parliamentary Privileges Committee from 7 March 1944 to 4 December 1947.

After the United Australia Party and the Country Party lost heavily in the 1943 federal election, McEwen was elected deputy leader of the Country Party. When the Curtin War Cabinet discussed the need for a direct report on the situation in New Guinea in addition to General Macarthur's reports, McEwen was considered. So, briefly, was newspaperman Keith Murdoch. On the Advisory War Council McEwen advocated independent and first-hand reports of the New Guinea situation, and was critical of the northern air defence strategy.

In 1944 the Curtin government held a referendum aimed at extending the federal government's wartime powers to assist in repatriation and post-war reconstruction programs. McEwen was a leading figure in the 'No' campaign, arguing that constitutional change was not a priority.

In April 1945 McEwen went to San Francisco as an adviser to the Australian delegation to the conference held to establish the United Nations. The delegation was led by Labor deputy Prime Minister Frank Forde, who became caretaker Prime Minister on his return to Australia after the death of Ben Chifley on 5 July 1945. McEwen returned to Australia in August, shortly after United States bombers had dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki. The war in the Pacific ended on 15 August.

During November 1947 Australia entered the General Agreement on Tariffs and Trade (GATT), aimed at reducing world tariffs, avoiding trade wars and stimulating trade. Australia began the process of tariff reduction which was to continue throughout the remainder of the 20th century. He was the key figure in negotiating Australia's international trade agreements throughout the 1950s-60s. He travelled widely in Europe, Asia, North America and Pacific regions, attending conferences on trade and tariffs.

Australia's trading arrangements changed significantly during McEwen's period of responsibility for the trade portfolios in the 1950s-60s. During the 1940s the UK had taken over 50% of Australia's exports and provided 40% of its imports, but by the early 1960s these figures had dropped to 20% and 30% respectively. UK efforts to join the European Economic Community (EEC) prompted Australia to diversify its markets, establishing new outlets for its wheat, wool, beef, iron ore and bauxite in Japan, USA, China and the Eastern European Communist bloc. By 1967, six years before UK entered the EEC, Japan had replaced UK as Australia's principal trading partner.

During the four years of the Labor government of Ben Chifley, Fadden and McEwen worked to strengthen support for the Country Party. From the remnants of the United Australia Party, the new Liberal Party was formed and Robert Menzies became leader. At the election on 19 December 1949, a Liberal Party-Country Party coalition was returned with a large majority, and Menzies became Prime Minister. McEwen was now member for Murray, a new division created within his former Indi electorate by the electoral redistribution in 1949.

In October 1950 McEwen travelled to London as Australian representative on an international group investigating wool trading, and the following year he went to Britain for three months for meetings relating to export contracts for primary produce and supplies of raw materials for post-war reconstruction. In November and December 1952, he attended the Commonwealth Financial and Economic Council in London. The following year he was appointed to the Privy Council.

In the new Cabinet sworn in on 11 January 1956, McEwen became Minister for Trade, taking the Commerce responsibilities from his former portfolio to an influential new department. A separate Department of Primary Industry was established and experienced officials moved from the former Agriculture Department to staff it. The new Minister for Primary Industry was Liberal member William McMahon. He was a novice in rural matters and it was assumed that he would follow the lead of the Country Party and in looking after the core interests of their constituents.

In June and July 1956 McEwen attended the conference of Commonwealth Prime Ministers in London. He returned in November that year for negotiations reviewing the Britain-Australia trade agreement. The following June he went to Japan with senior trade officials and negotiated a controversial Australia-Japan trade agreement. The agreement was opposed by manufacturers and trades unions, and by those who continued to see Japan as an enemy - the peace treaty with Japan had been signed only six years earlier.

After Arthur Fadden retired as leader of the Country Party, John McEwen was elected his successor on 26 March 1958 and consequently became deputy Prime Minister. From August to October 1958 McEwen visited Malaya and Ceylon, and led the Australian delegation to the Commonwealth Trade and Economic Conference in Montreal, Canada.

Between April 1959 and October 1960, McEwen acted four times as Prime Minister while Robert Menzies was overseas, and as Treasurer while Harold Holt was overseas in October 1960. Trade negotiations in the period leading up to Britain's entry into the European Economic Community were a major concern for the government. A fifth of Australia's primary production still went to British markets and the Country Party was keen to negotiate with Britain about the change. In 1962 and 1963 McEwen travelled to the United States, Canada, Britain and Europe for discussions about the effects on Australian trade of Britain's entry into the European Economic Community.

In July 1962 Leslie Bury, Liberal minister assisting Treasurer Harold Holt, was reported to have said that the impact of Britain joining the European Economic Community would be less damaging than Cabinet had advised parliament. Menzies suspended Bury. Although McEwen was widely thought to have insisted on this, Mary Byrne, his private secretary at the time and later his second wife, recalled Menzies' phone call that day. The conversation was brief and the decision made by Menzies before McEwen had even read the story in that day's papers. In any case, France blocked Britain's application to join the common market at that time.

After Arthur Fadden's retirement from parliament in December 1962, the Country Party never again held the Treasury portfolio. As Minister for Trade, McEwen was often in conflict with Treasury on economic policy, but McEwen also differed at times from his rural constituents on trade policy. Rural producers benefited from low tariff barriers on imported agricultural inputs and traditionally favoured free trade. McEwen saw protection of Australian industry as vital, and took this position in meetings on international trade arrangements under the General Agreement on Tariffs and Trade. In July and August 1963 McEwen attended trade talks in Hong Kong, Japan and the Philippines, and secured a renewed Australia-Japan trade agreement. The coalition had lost ground in the December 1961 election, and both parties responded to this electoral message with a revision of policy and of the policy-making process. In November 1963 they were rewarded with a more comfortable win.

In the new Cabinet sworn in on 18 December 1963, McEwen's portfolio was now titled Trade and Industry, reflecting the establishment of an office of secondary industry in his department. McEwen was in charge of the key areas of commerce and trade for 20 years. This extended period of responsibility meant he developed close and long-term relationships with senior officials like John Crawford and Alan Westerman, as well as an influential network of business and government contacts in Australia and overseas. He went regularly to London for Commonwealth trade meetings, often combined, as in March and April 1964, with international trade and development conferences in Geneva. In June 1964 McEwen attended the inauguration of the Papua and New Guinea House of Assembly in Port Moresby - an important step towards the Territory's 1975 independence from Australian administration.

In 1964 an Australian contingent of advisors had been sent to South Vietnam to assist the United States and South Vietnamese military effort in the war against Communist North Vietnam. In November 1964 Cabinet decided to reintroduce conscription, and in April 1965 Prime Minister Robert Menzies announced that Australian troops would be sent to Vietnam the following month. In a speech broadcast during the campaign for the Senate election in December 1965, McEwen argued that "in the battle for freedom - the battle against Communism - export revenue from mines, factories and farms" was the necessary basis for a strong and well equipped defence force. In June and July 1965, McEwen was both acting Prime Minister and acting Minister for External Affairs when Robert Menzies and Paul Hasluck were overseas. In September and October, McEwen attended an international sugar conference in Geneva.

In January 1966 Prime Minister Robert Menzies resigned after a record 16-year term. The Liberal Party elected Harold Holt the new leader and William McMahon as deputy leader. McMahon also succeeded Holt as Treasurer. In May and June 1966 McEwen represented Australia in trade talks in London, Poland, Bulgaria and the United States. The following year his talks with British ministers in London in April were followed by the final 'Kennedy' round of negotiations on the General Agreement on Tariffs and Trade.

At the federal election in November 1966 the Holt-McEwen coalition was returned with an increased majority. McEwen was acting Prime Minister in the first week of February 1967, and then went to New Zealand for trade talks. Ten days before the opening of the 26th parliament on 21 February, Anne McEwen died. An invalid confined to a wheelchair for some years, Anne McEwen had retained her interest in politics from her schooldays and through the 45 years of the McEwens' marriage.

In May 1967 Britain made a second and now successful bid for entry to the European Economic Community. McEwen went to Brussels, Bonn, Paris and London for discussions, returning to be acting Prime Minister when Holt went overseas at the end of the month. In November and December 1967, McEwen was in Geneva for a world trade ministers' meeting on the quota proposals of the US Congress. He then attended the Organisation of Economic Cooperation and Development ministerial council meetings in Paris, and went to Hungary for trade talks.

McEwen's key preoccupation on his return was the government's response to Britain's decision to devalue the pound sterling. He arrived in Sydney on 10 December and was met by the head of the Department of Trade, Alan Westerman, Country Party ministers Doug Anthony and Ian Sinclair, and his press secretary Robert Macklin. Cabinet had decided on 20 November not to follow the British move with a devaluation of the Australian dollar. This would impact on primary producers, particularly those with current export contracts, and was thus a major concern for the Country Party. McEwen's public statement protested the Cabinet decision and was widely reported.

McEwen returned to Canberra on 12 December and Prime Minister Harold Holt, with uncharacteristic firmness, extracted an assurance that his criticism of Cabinet would not recur. But the issue caused the eruption of McEwen's ongoing enmity with Treasurer and deputy Liberal leader William McMahon. Their bitter rows had long been a source of material - and leaks - for political reporters. Publications like Don Whitingon's Inside Canberra and Frank Browne's column "Things I hear" were as avidly read for the latest news by parliamentarians, as well as the public.

Two days before McEwen had returned to Australia, Governor-General Richard Casey had met McMahon to seek his commitment to reduce the conflict, the leaks and the danger of coalition instability. This unusual intervention McMahon later recorded in a written 'aide-memoire'. There he noted Casey's comment that he had 'talked to Spry' about leaks published in Inside Canberra. Director of Intelligence Charles Spry had responded that this was not his business, but he and the Governor-General had nonetheless discussed whether the Inside Canberra journalists had sources in all departments.

According to McMahon's notes, Casey also discussed his own relationship with McEwen, saying when they were both in Menzies' Cabinet, he had felt McEwen disliked him, but now a friendship had developed and they could trust each other. The Governor-General said McEwen "was a very difficult person to deal with as he lived on the edge of his nerves all the time and you never knew when he would break out". He told McMahon that care was needed to ensure McEwen did not resign until the Country Party succession was settled between Doug Anthony and Ian Sinclair.

Despite the Governor-General's attempt at mediation, for the next week McMahon and McEwen were locked in battle. McMahon minuted every conversation. He met Holt before the Cabinet meeting on Friday, 15 December and insisted Holt have a copy of the record of his 8 December meeting with the Governor-General. Casey had apparently already given Holt his own note of the meeting. That evening, Holt had both documents in his briefcase when he left for a weekend at the Holts' holiday house in Portsea, Victoria.

On Sunday, 17 December, the Prime Minister disappeared while swimming at a beach near the Portsea house. The Governor-General's role was crucial in the events that led to deputy Prime Minister John McEwen, not the deputy leader of the majority party, William McMahon, becoming the next Prime Minister.

Australia's Constitution requires the Governor-General, as representative of the Head of State, to act only on the advice of his ministers. The two precedents were the Duke of Gloucester's commissioning of deputy Labor leader Frank Forde in July 1945, after the death of Labor Prime Minister John Curtin, and Lord Gowrie's commissioning of Country Party leader Arthur Fadden in April 1939, after the death of United Australia Party Prime Minister Joseph Lyons. In the latter case, the reasoning was that the Country Party deputy Prime Minister was chosen only because there was no deputy leader of the majority party. Instead, the Governor-General acted on the advice of Attorney-General Nigel Bowen and senior coalition ministers, and after 48 hours deemed the Prime Minister dead. He then commissioned John McEwen as Prime Minister of a 'caretaker' government until a Liberal leader was elected. The temporary nature of the role rested only on agreement, as the term of a government is decided by the parliament, not the Governor-General.

When Holt disappeared on 17 December 1967, there was a two-day hiatus before the Liberal-Country Party coalition could accept the probability of his death. McEwen stepped into the breach as caretaker Prime Minister while the coalition elected a new man for the post. As a Country Party man, McEwen could have little hope for the top job. But as the principal power-broker of his party, he could exert remorseless pressure.

McMahon's 'aide-memoire' revealed a Governor-General apparently as concerned as the government with preserving the coalition. On Monday, 18 December, the day after Holt disappeared, McEwen gave the Governor-General an ultimatum that he would not serve in a government led by McMahon. McEwen also told McMahon he would not serve under him because he did not trust him. Then, after securing the Country Party ministers' agreement, McEwen made his position public. He declared publicly that he would not serve under William MacMahon, who was the Liberal Party's first choice for Prime Minister.

When Gorton took over as Prime Minister, McEwen returned to his post of Minister for Trade where he had already shown himself to be a tireless negotiator for the benefit of primary producers. In 1968 he secured an international sugar agreement which was applauded by Australian planters. The present worldwide network of Australian Trade Commissions also owes a great deal to McEwen initiatives.

He retired from Parliament in 1971 and enjoyed nine peaceful years before his death in 1980.