Simon Hannah is a writer, activist, and trade unionist living in South London. He is an assistant branch secretary in UNISON and has written several books, including A Party With Socialists In It: A History of the Labour Left, which was a Guardian Book of the Day.

Nadia Whittome is Labour MP for Nottingham East. On her election in December 2019 at the age of 23, Whittome became the youngest MP in the House of Commons. She is a member of the Socialist Campaign Group of Labour MPs.

John McDonnell is a British Labour Party politician first elected in 1997, who served as Shadow Chancellor of the Exchequer from 2015 to 2020, in the later years under the leadership of Jeremy Corbyn. Sitting on the left of the party, he served as chair of the Socialist Campaign Group in Parliament and the Labour Representation Committee as well as the Public Services Not Private Profit Group. In 2024 he was suspended from the party as a result of voting to scrap the two child benefit cap.