In addition to Maclean's influence, Maxton was moved towards socialism by a meeting which he attended in Paisley which was addressed by party leader Philip Snowden.

Historian Keith Middlemas offers this vivid description: He was well-known as a platform orator with a thin hatchet face and mane of long black hair which fell across his face giving it a saturnine and piratical appearance, but although he was an established speaker and propagandist for the ILP, his considerable intellect had been somewhat masked by the showman's facility.

In his next electoral attempt, Maxton was successful, winning a seat as Member of Parliament (MP) for Glasgow Bridgeton in the 1922 general election.

In 1923, his parliamentary privileges were temporarily removed when he called the Conservative MP Sir Frederick Banbury a "murderer", following the government's decision to withdraw school milk.

[12] In 1933, when then-Prime Minister MacDonald made a particularly meandering and incoherent speech to Parliament, it was interrupted by Maxton calling out: "Sit down, man, you're a bloody tragedy.

Maxton wrote of him: "We are still too near to [Lenin] in time, too close to the happenings incidental to his work, too much under the influence of partisan antipathies or sympathies to venture final assessments.

It is possible to say that this man, quiet, unassuming, unimposing, set himself a task of immense size when still a boy, and stuck to it tenaciously to the end of his life.

[17] With Henk Sneevliet of the Dutch revolutionary communist party the RSP, Maxton headed deputations to civil war Spain on behalf of the international campaign for socialists there persecuted after the May Days of Barcelona.

Victor Serge described "Maxton the imperturbable, with his angular face and steady grey eyes, pipe in mouth, heard the Spanish ministers Irujo and Zugazagoita — honest Republicans who had done their utmost to save the victims—reply to him: 'These abominable acts are done against our will.

[18] In his diary for 3 September 1939, Sir Ralph Glyn reported that "James Maxton, the pacifist, rose, gaunt, a Horseman from the Apocalypse, doom written across his face," and declared, "Don't let's talk of national honour: what do such phrases mean?

"[19] During the Second World War, Maxton visited HM Prison Brixton to see Oswald Mosley, the leader of the British Union of Fascists, who was then being detained under the Defence Regulations.

[citation needed] His biographer Graham Walker concludes: Maxton heavily influenced his family's political opinions, and his mother and all his siblings also joined the ILP.

Former British Prime Minister, Gordon Brown, published a biography, Maxton, based on his PhD thesis at the University of Edinburgh.