Margaret was sent to Roedean in September of 1907. In her autobiography, Growing Up Into Revolution (1949) she claimed: "I have never understood why my parents sent me to Roedean. To remove me from the home was understandable. I was the wrong sort of cuckoo in a horridly alien nest. The cross was too wide, and Roedean was, emphatically, the wrong sort of school for me. But I would go further and say it was not a good sort of school at all. It was very expensive; I only got in as the winner of the single annual scholarship."
In October 1911 she entered Girton College. After reading the work of J. A. Hobson, H. G. Wells, Sidney Webb, Beatrice Webb, George Bernard Shaw and Noel Brailsford she became a socialist, feminist and an atheist. In 1914 she left the University of Cambridge to take up a position teaching classics in St Paul's Girls' School.
On the outbreak of the First World War Cole became active in the peace movement. This brought her into contact with leading figures in the Independent Labour Party. In 1915 she began working part-time for the Fabian Research Department, where she met George Douglas Cole. He was leader of what became known as Guild Socialism. This movement advocated workers' control of industry through the medium of trade-related guilds. Other supporters included William Mellor, J. A. Hobson, Frank Horrabin, R. H. Tawney, Leonard Hobhouse and Samuel Hobson. This group formed the National Guilds League in 1915.
Margaret joined the campaigned against conscription. After the passing of the Military Service Act, the No-Conscription Fellowship mounted a vigorous campaign against the punishment and imprisonment of conscientious objectors. About 16,000 men refused to fight. Most of these men were pacifists, who believed that even during wartime it was wrong to kill another human being. This included her brother, Raymond Postgate. and her lover, George Douglas Cole.
Margaret welcomed the Russian Revolution in November 1917. As she explained in her autobiography, Growing Up Into Revolution (1949): "On the way to the office we bought our newspapers and read with incredulous eyes that the Russian people, the workers, soldiers, and peasants, had really risen and cast out the Tsar and his government, who were to our minds the arch-symbols of black oppression in the world - far worse than the Prussians. On that day we did not work at all in the office; we danced round the tables and sang, and went to celebrate. Nor was it merely our small group that was delighted; throughout Britain everyone with an ounce of Liberalism in his composition rejoiced that whatever might come next tyranny had fallen, and thousands of them gathered in the Albert Hall and wept unashamedly as they paid tribute to those who had suffered in Siberia or in the Tsarist prisons. The news of Russia put immense heart into left-wing forces all over the country. It seemed as though there might be something good coming out of the war after all; for if the Russian people could overthrow their government, could not the Germans and the Austrians - or the French, or the British?"
Margaret married George Douglas Cole in August 1918. They moved to Oxford where Margaret taught evening classes and worked part-time for the Labour Research Department. She gave birth to Janet Elizabeth Margaret (February 1921) and Anne Rachel (October 1922). In 1924 the couple moved to Oxford where they both became involved in writing and teaching. Cole became Labour correspondent of the Manchester Guardian and after the publication of several books, including Guild Socialism Restated (1920), William Cobbett (1925) and Robert Owen (1925), Cole was appointed as Reader in Economics at University College.
In 1926 the couple gave support to the miners during the General Strike. They were regular visitors to the home of Beatrice Webb. She wrote in her diary on 5th September: "G.D.H. Cole and his wife - always attractive because they are at once disinterested and brilliantly intellectual and, be it added, agreeable to look at - stayed a weekend with us and later came on to the T.U.C. Middle age finds them saner and more charitable in their outlook... He is still a fanatic but he is a fanatic who has lost his peculiar faith... despite a desire to be rebels against all conventions, the Coles are the last of the puritans."
In 1931 Margaret and G.D.H. Cole created the Society for Socialist Inquiry and Propaganda (SSIP). This was later renamed the Socialist League. Other members included William Mellor, Charles Trevelyan, Stafford Cripps, H. N. Brailsford, D. N. Pritt, R. H. Tawney, Frank Wise, David Kirkwood, Clement Attlee, Neil Maclean, Frederick Pethick-Lawrence, Alfred Salter, Jennie Lee, Harold Laski, Frank Horrabin, Ellen Wilkinson, Aneurin Bevan, Ernest Bevin, Arthur Pugh, Michael Foot and Barbara Betts. Margaret Cole admitted that they got some of the members from the Guild Socialism movement: "Douglas and I recruited personally its first list drawing upon comrades from all stages of our political lives." The first pamphlet published by the SSIP was The Crisis (1931) was written by Cole and Bevin.
According to Ben Pimlott, the author of Labour and the Left (1977): "The Socialist League... set up branches, undertook to promote and carry out research, propaganda and discussion, issue pamphlets, reports and books, and organise conferences, meetings, lectures and schools. To this extent it was strongly in the Fabian tradition, and it worked in close conjunction with Cole's other group, the New Fabian Research Bureau." The main objective was to persuade a future Labour government to implement socialist policies.
In April 1933 G.D.H. Cole, R. H. Tawney and Frank Wise, signed a letter urging the Labour Party to form a United Front against fascism, with political groups such as the Communist Party of Great Britain. However, the idea was rejected at that year's party conference. The same thing happened the following year. Although disappointed, the Socialist League issued a statement in June 1935 that it would not become involved in activities definitely condemned by the Labour Party which will jeopardise our affiliation and influence within the Party."
Stafford Cripps was another advocate for an United Front: "Up till recent times it was the avowed object of the Communist Party to discredit and destroy the social democratic parties such as the British Labour Party, and so long as that policy remained in force, it was impossible to contemplate any real unity... The Communists had... disavowed any intention, for the present, of acting in opposition to the Labour Movement in the country, and certainly their action in many constituences during the last election gives earnest of their disavowal." Aneurin Bevan added: "It is of paramount importance that our immediate efforts and energies should be directed to organising a United Front and a definite programme of action."
In 1936 the Socialist League joined forces with the Communist Party of Great Britain, the Independent Labour Party and various trades councils and trade union brances to organize a large-scale Hunger March. Aneurin Bevan argued: "Why should a first-class piece of work like the Hunger March have been left to the initiative of unofficial members of the Party, and to the Communists and the ILP... Consider what a mighty response the workers would have made if the whole machinery of the Labour Movement had been mobilised for the Hunger March and its attendant activities."
Although Margaret Cole and G.D.H. Cole were seen as major figures on the left, Beatrice Webb believed that they now moderated their opinions. In a diary entry on 20th July 1936 she wrote. "Our old friends the Coles came for the night; middle-aged and thoroughly stabilized in all their relationships, endlessly productive of books, whether economic and historical treatises or detective stories, mutually devoted partners and admirable parents of their promising children, they lead their little troop of admiring disciples along the middle way of politics, rather to the right of the aged Webbs - a curious commentary on the world-be revolutionary guild socialist movements of the second decade of the twentieth century."
The United Front campaign opened officially with a large meeting at the Free Trade Hall in Manchester on 24th January, 1937. Three days later the Executive of the Labour Party decided to disaffiliated the Socialist League. They also began considering expelling members of the League. G.D.H. Cole and George Lansbury responded by urging the party not to start a "heresy hunt".
Arthur Greenwood was one of those who argued that the rebel leader, Stafford Cripps, should be immediately expelled. Ernest Bevin agreed: "I saw Mosley come into the Labour Movement and I see no difference in the tactics of Mosley and Cripps." On 24th March, 1937, the National Executive Committee declared that members of the Socialist League would be ineligible for Labour Party membership from 1st June. Over the next few weeks membership fell from 3,000 to 1,600. In May, Margaret Cole and other leading members decided to dissolve the Socialist League.
Margaret Cole and her husband worked together to produce Intelligent Man's Review of Europe Today (1933) and The Condition of Britain (1937). She followed this by two books on her own: The New Economic Revolution (1938) and Marriage Past and Present (1938), which outlined a theory of socialist feminism. She lost her belief in pacifism with the rise of Adolf Hitler in Nazi Germany and as a result, she gave her full support to Britain's involvement in the Second World War.
A Labour Party member of the London County Council, Cole was an important figure in the early experiments with comprehensive education. As well as editing the diaries of Beatrice Webb, Cole also wrote several books including an autobiography, Growing Up into Revolution (1949), The Story of Fabian Socialism (1961) and G. D. H. Cole (1971).
According to her biographer, Marc Stears: "Towards the end of her husband's life Margaret Cole increasingly turned to historical studies as she attempted to document the considerable contribution that the couple and their friends had made to the British left.... She broke an informal agreement with R. H. Tawney by producing the first edited collection of articles on the work of Beatrice Webb, generating ill feeling which she perpetuated after his death... Despite these controversies, and a reputation for being personally abrasive, Margaret Cole was still generally respected on the left in the post-war world."