Brake was Liberal Democrat MP for Carshalton and Wallington 1997-2019. Prior to his election, Brake served as a councillor in Hackney 1988-90 and Sutton 1994-98. In parliament, Brake spoke on a range of issues including transport, international development and local government. In 2010 he was appointed co-chair of the Liberal Democrat Joint Committee on Home Affairs, Justice and Equalities and served as Deputy Leader of the House of Commons from 2012 to 2015. Following the 2015 election Brake was appointed as Lib Dem foreign affairs spokesperson and Chief Whip and from June 2017 he served as spokesperson on International Trade and Exiting the European Union. Brake lost his seat at the 2019 general election. In October 2020, he was appointed director of Unlock Democracy.