It has been traditionally used as the office of the Chief Whip although the upper floor forms part of the residential apartment for the Prime Minister of the United Kingdom.
[1] Under the 2019–2024 government the building was used to house the Prime Minister's Press Office and Strategic Communications Unit.
It was purchased that year by the Crown, and was first used to house the Judge Advocate General of the Armed Forces.
[5] After that moved out in 1879, the house at 12 Downing Street was for many decades used as the office of the Chief Whip of the Government,[7] and also for parliamentary dinners.
[11] Following the breakup of the coalition government, the Liberal Party Chief Whip John Gulland was blamed in some parts of the media for disconnecting the phone line running to 12 Downing Street.