 Browne was Policy Director for Economic Development for Boris Johnson, the Mayor of London, in charge of economic and business policy for London, sitting on the board of the London Development Agency, and as an observer on the boards of the London Skills and Employment Board, and TheCityUK, which represents UK financial services.He was also chairman of the Mayor's Digital Advisory Board.On Saturday 20 July 2019, Browne was announced as the Conservative parliamentary candidate for South Cambridgeshire.