The Metropolitan Police Authority (MPA) (2000–2012) was the local police authority responsible for scrutinising and supporting the work of the Metropolitan Police Service, the police force for Greater London (excluding the City of London Police area). The establishment of the MPA in 2000 marked a fundamental change in the policing of London; establishing, for the first time, a local police authority for the metropolis, with the aim of ensuring that the Metropolitan Police Service was democratically accountable.
The MPAs ceased to exist on 16 January 2012, when its functions were transferred to the Mayor's Office for Policing and Crime (MOPAC).
More information on the Wikipedia page [1].