[2] The eldest son of The Revd Canon Gordon Tarry, a Church of England clergyman, he grew up on St. Andrews Road and attended Highlands Primary School in Ilford.

His family later moved to Seven Kings, and Tarry completed his secondary education at St Edward's Church of England School in Romford.

[14]In 2016 Tarry worked under Jon Lansman's supervision as a director of Jeremy Corbyn's successful Labour Party leadership campaign.

[15] He subsequently worked as the national political officer for the TSSA trade union, and served as the president of a thinktank, the Centre for Labour and Social Studies (CLASS).

[22] On 4 October 2019, the evening before members were due to vote, a rival candidate, Redbridge Council leader Jas Athwal, was suspended from the party over an allegation of sexual harassment.

He further stated, "As someone who has worked with many interfaith groups and organisations, including Searchlight and Hope not Hate, specifically to fight antisemitism and racism, this is something I care deeply about and would never seek to downplay".

[39][40][41] The summer of 2022 saw significant amounts of industrial unrest, with[42][43] Keir Starmer instructing members of his shadow cabinet to refrain from joining picket lines.

[45][46] Tarry was dismissed from his position as Shadow Minister for Buses and Local Transport on 27 July after he had appeared on a rail strike picket at Euston railway station.

[47][48] However, his sacking was criticised by trade union leaders, and Tarry wrote in a newspaper opinion piece that "failing to join the striking rail workers on a picket line would have been an abject dereliction of duty for me as a Labour MP".

[55] In 2023, Tarry's letter on the subject to then-Home Secretary Suella Braverman was supported by Fatboy Slim, Billy Bragg and Olugbenga Adelekan as well as 31 MPs.