The son of an Irish labourer named Patrick Clynes, he was born in Oldham, Lancashire, and began working in a local cotton mill when he was ten years old.

[2] Aged sixteen, he wrote a series of articles about child labour in the textile industry, and the following year he helped form the Piercers' Union.

During the First World War, Clynes was a supporter of British military involvement (in which he differed from Ramsay MacDonald), and, in 1917, became Parliamentary Secretary of the Ministry of Food Control in the Lloyd George coalition government.

He was held in considerable respect and affection in the Labour Party and, although lacking the charisma of MacDonald, was a wily operator who believed all resources available should be used to advance the material of the working classes.

Clynes was a critic of government policy towards the Irish population in the years after 1918, and attacked 'a recurring system of coercion' which had left Ireland "more angry and embittered .

[2] In that role, Clynes gained literary prominence when he explained in the Commons his refusal to grant a visa[10] to the Russian revolutionary Leon Trotsky, then living in exile in Turkey, who had been invited by the Independent Labour Party to give a lecture in Britain.

Clynes had then been immortalised by the scathing criticism of his concept of the right to asylum, voiced by Trotsky in the last chapter of his autobiography My Life, entitled "The planet without visa".

[11] In 1931, Clynes sided with Arthur Henderson and George Lansbury, against MacDonald's support for austerity measures to deal with the Great Depression.