The Greater London Authority (GLA), colloquially known by the metonym "City Hall", is the devolved regional governance body of Greater London. It consists of two political branches: the executive Mayoralty (currently led by Sadiq Khan) and the 25-member London Assembly, which serves as a means of checks and balances on the former. Since May 2016, both branches have been under the control of the London Labour Party. The authority was established in 2000, following a local referendum, and derives most of its powers from the Greater London Authority Act 1999 and the Greater London Authority Act 2007.