Moses Ayrton (Airton) was born at Yeadon, Yorkshire, England, on 15 July 1878. He was the son of Moses Airton, a woollen waste dealer, and his wife, Martha Chappell. Moses junior became a grocer's assistant. A Wesleyan Methodist lay reader, at age 18 he offered himself for ordination. He married Ethel Firth at Rawdon, Yorkshire, on 6 November 1900.
Ayrton emigrated to New Zealand in 1908, serving from 1910 to 1919 as a home missionary in North Taranaki, Tauranga, Greymouth, Rūnanga, Denniston–Granity and Denniston–Millerton. After his appointment to Tauranga his wife and three children joined him; two further children were born in New Zealand.
Ayrton had been a member of the Independent Labour Party in Britain. His Christian beliefs, compassion, keen social conscience and first-hand experience of industrial conditions helped shape his socialist beliefs, which were confirmed by his years among mining communities on the West Coast. Ayrton's sympathies were made abundantly clear in October 1912 when, along with Bob Semple, Harry Holland and others, he spoke at a rally in Greymouth protesting at government and police action against striking miners at Waihi. But his basic attitudes were less radical than his rhetoric and political links might suggest, and he was described as a philosophical and evolutionary socialist.
Moses Ayrton was a member of the local Social Democratic Party executive, represented it at national conferences and was national vice president in 1915 and 1916. He was among the nominators of Paddy Webb as SDP candidate for the Grey electorate in 1913 and 1914 and was his campaign chairman on both occasions. Ayrton also argued strongly that labour factions should unite to increase their political effectiveness. In Rūnanga he was on the school committee, borough council and Grey Hospital and Charitable Aid Board. During his years on the West Coast he lectured for the WEA on English literature and economics.
Ayrton was among the relatively few Methodists who publicly took issue with official Methodist support for the First World War, which he believed constituted the death throes of capitalism. In August 1915, deputising for the mayor at a public meeting in Rūnanga, he questioned the continuance of the war and, in March 1916, was one of those behind a decision by the Rūnanga Borough Council to hold a meeting on war issues; a resolution opposed recruitment and called for negotiations to ensure an early peace. He opposed conscription and attended the labour movement's anti-conscription conference in 1916. He was also a strong advocate of temperance: a 'sober democracy', he remarked, was likely to be a better one and the 'liquor interests are the same as all other capitalistic forces which have got to be fought by the workers in all lands.'
Ayrton's party political activities during his Rūnanga years generated some local opposition and earned him a rebuke from T. G. Brooke, the general secretary of the Home Mission and Church Extension Fund, who told Ayrton that such participation by ministers or home missionaries was 'against the interest and harmony of the Connexion, and also against our usage as a Church'.
Ayrton took up an appointment at Feilding–Halcombe in 1918 but resigned in March 1919 following a difference of opinion with the Home Missions committee. An ordained minister had been appointed to Halcombe, and Ayrton was left with Feilding only and an income he deemed insufficient. He then went to Palmerston North as a WEA tutor. He became a popular speaker and stood (unsuccessfully) for the New Zealand Labour Party in Palmerston North in 1919. In 1920–22 he served as party secretary, a role in which he proved ineffective. In 1925 he stood (unsuccessfully) for the Raetihi Borough Council.
Ayrton's political activities seem to have ceased from the mid 1920s. In 1924 he was accepted as a probationer for ordained ministry and served at Waimarino (1924–25) and Ōtautau (1926–27). After his ordination in 1928 he served at Bluff (1928–30), Ōtaki (1931–33), Taitapu (1934–37) and Richmond (1938–40). He retired in 1945, but continued to perform some ministerial duties. Ethel Ayrton died on 23 October 1939. On 10 June 1948 Moses Ayrton married Grace Pinfold (née Darling), at Wellington. After some years of poor health he died at Wellington on 3 October 1950, survived by Grace, and by his children.