Downing Street Chief of Staff

The Downing Street Chief of Staff is the most senior political appointee in the Office of the Prime Minister of the United Kingdom, acting as a senior aide to the Prime Minister and a powerful, non-ministerial position within Her Majesty's Government.

The role of Chief of Staff when created had executive authority and at the time was referred to as "almost certainly the most powerful unelected official in the country", and possibly "the third most powerful altogether" after the Prime Minister and the Chancellor of the Exchequer. Since 2007 the role does not legally have executive authority, though the post holder remains a very senior adviser to the Prime Minister. The current Downing Street Chiefs of Staff are Fiona Hill and Nick Timothy.

The position of Downing Street Chief of Staff was created by Tony Blair upon becoming Prime Minister in 1997. The first Chief of Staff was Jonathan Powell, who held the post for ten years.

The Chief of Staff is an appointed special advisor or a career civil servant who is personally and politically close to the Prime Minister. The responsibilities of the post have varied according to the wishes of the sitting Prime Minister. However, since the holder is, owing to the nature of the post, at the centre of the Downing Street operation, he or she will always be influential and closely involved in government policy formulation and implementation, political strategy and communication, and generally advising the Prime Minister.

In 1997 Tony Blair gave his Chief of Staff, a special advisor, 'unprecedented powers' to issue orders to civil servants. Previously the Cabinet Secretary had been the most senior non-ministerial figure in the British Government, and along with the Principal Private Secretary to the Prime Minister had supported the Prime Minister in the running of 10 Downing Street. The relationship between the three posts was the basis for the BBC television series Yes, Prime Minister. Following the creation of the role, the Chief of Staff supplanted the Principal Private Secretary in running Downing Street operations and effectively replaced the power of the Cabinet Secretary in terms of co-ordinating government policy.