Michael Foot was educated at Plymouth College Preparatory School and at Leighton Park, a fee-paying school in Reading. He went on to read Philosophy, Politics and Economics at Wadham College, Oxford. Foot was the President of the Oxford Union.

On graduating with second-class honours in 1934, he took a job as a shipping clerk in Birkenhead. Foot was profoundly influenced by the poverty and unemployment that he witnessed in Liverpool, which were on a very different scale from anything he had seen in Plymouth. A Liberal up to this time, Foot was converted to socialism and he joined the Labour Party. He first stood for parliament at the age of 22 in the 1935 general election, when he contested Monmouth. During this election Foot criticised the Prime Minister, Stanley Baldwin, for seeking rearmament.

Michael Foot became a journalist, working briefly on the New Statesman, before joining the left-wing weekly Tribune when it was set up in early 1937 to support the Unity Campaign, an attempt to secure an anti-fascist United Front between the Labour Party and the parties to its left. On the recommendation of Aneurin Bevan, Foot was soon hired by Lord Beaverbrook to work as a writer on his Evening Standard. At the outbreak of the Second World War in 1939, Foot eagerly volunteered for military service, but he was rejected because of his chronic asthma. In 1940, under the pen-name “Cato” he and two other Beaverbrook journalists published Guilty Men, a Left Book Club publication virulently attacking the appeasement policy of the Chamberlain government that quickly became a run-away best-seller. The book was an attack on the politicians who were associated with appeasement. These included Neville Chamberlain, Lord Halifax, John Simon, Samuel Hoare, Ramsay MacDonald, Stanley Baldwin and Kingsley Wood.

Beaverbrook made Foot editor of the Evening Standard in 1942 at the age of 28. Foot was exceptionally well-off at this period, being paid nearly £4,000 a year by The Evening Standard, to which Beaverbrook would add an occasional “princely bonus” on his own account. Foot left the Standard in 1945 to join the Daily Herald as a columnist. He rejoined Tribune as editor from 1948 to 1952, and was again the paper's editor from 1955 to 1960. Throughout his political career he railed against the increasing corporate domination of the press, entertaining a special loathing for Rupert Murdoch.

Foot fought the Plymouth Devonport constituency in the 1945 general election. He won the seat for Labour for the first time, holding it until his surprise defeat by Dame Joan Vickers at the 1955 general election.

Until 1957, he was the most prominent ally of Aneurin Bevan, but the two men fell out after Bevan renounced unilateral nuclear disarmament at the 1957 Labour Party conference. Though then offered the safe Labour seat of Aberavon in south Wales, he determined to fight Plymouth Devonport again, only to go down once more to Joan Vickers in 1959.

Foot returned to parliament in 1960 at a by-election in Ebbw Vale in Monmouthshire, left vacant by Aneurin Bevan's death. Over the years he would develop a deep affection for the constituency. He had the Labour whip withdrawn in March 1961 after rebelling against the Labour leadership over air force estimates. He only returned to the Parliamentary Labour Group in 1963 when Harold Wilson became Labour leader after the sudden death of Hugh Gaitskell.

Harold Wilson offered Foot a place in his first government, but he turned it down. Instead he became the leader of Labour's left opposition from the back benches, dazzling the Commons with his command of rhetoric. He opposed the government's moves to restrict immigration, join the Common Market and reform the trade unions; he was against the Vietnam War and Rhodesia's unilateral declaration of independence, and he denounced the Soviet suppression of “socialism with a human face” in Czechoslovakia in 1968. In 1967, Foot challenged James Callaghan but failed to win the post of Treasurer of the Labour Party. After 1970, Labour moved to the left and Wilson came to an accommodation with Foot. In April 1972, he stood for the Deputy Leadership of the party, along with Edward Short and Anthony Crosland. Short defeated Foot in the second ballot after Crosland had been eliminated in the first.

When, in 1974, Labour returned to office under Harold Wilson, Foot became Secretary of State for Employment. In this role, he played the major part in the government's efforts to maintain the trade unions' support. He was also responsible for the Health and Safety at Work Act. Foot was one of the mainstays of the “No” campaign in the 1975 referendum on British membership of the European Economic Community. When Wilson retired in 1976, Foot contested the party leadership and led in the first ballot, but was ultimately defeated by James Callaghan. Later that year, Foot was elected Deputy Leader and he served as Leader of the House of Commons, which gave him the unenviable task of trying to maintain the survival of the Callaghan government as its majority evaporated.

Following the Labour Party's 1979 general election defeat by Margaret Thatcher, James Callaghan remained party leader for the next eighteen months before he resigned and Foot was elected Labour leader on 4 November 1980, beating Denis Healey in the second round of the leadership election (the last leadership contest to involve only Labour MPs). Foot presented himself as a compromise candidate capable, unlike Healey, of uniting the party, which at the time was riven by the grassroots left-wing insurgency centred around Tony Benn. When he became leader, Foot was already 67 years of age and growing increasingly frail. Two days later he fell downstairs and had his leg encased in plaster. The accident created an image of Foot which he was never able to throw off, that of an old man struggling gamely, but ineffectively, against manifold physical disabilities.

The Tory government was dividing the country and proving highly controversial as its monetarist economic policies to reduce inflation were contributing to a significant rise in unemployment which had helped plunge Britain's economy into recession earlier in 1980. Almost immediately after his election as leader Foot was faced with a serious crisis: the creation in early 1981 of a breakaway party by four senior Labour right-wingers, Roy Jenkins, Shirley Williams, David Owen and William Rodgers (the so-called “Gang of Four”), the Social Democratic Party. The SDP won the support of large sections of the media. He dismissed criticism that he allegedly wore a donkey jacket [in fact, it was more of a duffle coat] to the 1981 Remembrance Service at the Cenotaph, but the image unfortunately stuck.

In the June 1983 general election, Foot's Labour Party lost to the Conservatives in a landslide - a result which had been widely predicted by the opinion polls since the previous summer. The SDP might have succeeded in its goal of “breaking the mould” of British politics if the SDP had pushed Labour into third place at the 1983 election, but Labour held on to second - just. It won 27.6 per cent of the votes to the SDP-Liberal Alliance's 25.4 per cent. Foot resigned days after the election and was succeeded as leader on 2 October by Neil Kinnock.

Foot took a back seat in Labour politics after 1983 and retired from the House of Commons in 1992 but remained politically active. Friends admitted that Michael Foot did not agree with all the actions since 1997 of Tony Blair - whom he rightly marked out as a man with a great future when he stood in the Beaconsfield by-election in 1982 - and Gordon Brown. But he never criticised them, remaining wholly loyal to the Labour Party and its successive leaders throughout his long old age.

Foot remained a high-profile member of the Campaign for Nuclear Disarmament. He wrote several books, including highly regarded biographies of Aneurin Bevan in two substantial volumes and of H. G. Wells. Though Foot is considered by many a failure as Labour leader, his biographer Mervyn Jones strongly makes the case that no one else could have held Labour together at the time, particularly in the face of the strength of Militant tendency. Foot is remembered with affection in Westminster as a great parliamentarian. He was widely liked, and admired for his integrity and generosity of spirit, by both his colleagues and political opponents. Foot was a passionate supporter of Plymouth Argyle Football Club from his childhood. He served for several years as a director of the club, seeing two promotions under his tenure.

Michael Foot was married to the film-maker, author and feminist historian Jill Craigie (1911-1999) from 1949 until her death. They had no children. A staunch republican (though actually well-liked by the Royal Family on a personal level), Foot rejected honours from the Queen and the government, including a knighthood and a peerage, on more than one occasion. Michael Foot died at his Hampstead (London) home after a long illness on 3rd March 2010 at the age of 96. He was cremated 15 March. There are two substantial and worthwhile biographies - by Mervyn Jones (1994) and Kenneth O. Morgan (2007).