John Martin McDonnell is a seasoned British politician who serves as Member of Parliament for Hayes and Harlington since May 1997 and also remained Shadow Chancellor of the Exchequer from 2015 to 2020. A Labour Party member, McDonnell earlier served as Member of the Greater London Council for Hayes and Harlington and Deputy Leader of the Greater London Council. He chaired the Labour Representation Committee, the Public Services Not Private Profit group as well as the Socialist Campaign Group in parliament. He lost to Gordon Brown during the 2007 Labour Party leadership election following resignation of Tony Blair. A leading figure on the left-wing of the party, McDonnell also acts as parliamentary convenor of the Trade Union Co-ordinating Group of eight left-wing trade unions. After Jeremy Corbyn became Labour leader in 2015, he inducted McDonnell as Shadow Chancellor of the Exchequer to his Shadow Cabinet. During his tenure as Shadow Chancellor, McDonnell led the development of Labour’s new economic programme and pledged to increase spending on infrastructure and research.