How is the Prime Minister appointed?

Sir Keir Starmer has announced his intention to resign as Prime Minister once a successor as leader of the Labour Party has been chosen.

This briefing looks at what happens when a Prime Minister formally resigns and the King appoints a successor, based upon prime ministerial memoirs and other sources.

The decision

The Cabinet Manual, which sets out the main laws, conventions and rules on the operation of government, states that Prime Ministers “hold office unless and until they resign”. Historically, the Monarch could dismiss a Prime Minister and make a personal choice of successor. Today it is for political parties “to determine and communicate clearly to the Sovereign who is best placed to be able to command the confidence of the House of Commons”.

If a Prime Minister chooses to resign when their administration has an overall majority (as in 2022 – twice – and June 2026), the practice is for the party in government (and its members) to identify who can be chosen as the successor, by whatever means internal party rules stipulate. The Prime Minister only formally resigns once this process is over. Whether doing so amounts to a “duty” has been questioned by the House of Lords Constitution Committee.

If an incumbent Prime Minister’s party wins an overall majority in a general election (as in December 2019), then they continue in office, their “authority” being “unbroken”, although by custom they will seek an audience with the Monarch.

If an election results in an overall majority for a different party (as in July 2024), then the incumbent Prime Minister resigns, and the Monarch invites the winning party’s leader to form a government. There will sometimes be a telephone call in which the incumbent concedes defeat to the Leader of the Opposition. If the election result is unclear (as in May 2010) then political parties must establish who is able to form the next government.

Any degree of personal discretion over the choice of a Prime Minister was last exercised in 1963 by Queen Elizabeth II, following Harold Macmillan’s resignation. Even then, her choice of Sir Alec Douglas-Home followed broad consultation within the Conservative Party.

As the constitutional expert Professor Rodney Brazier has observed:

The Sovereign could lawfully appoint anyone to be Prime Minister, but is guided by constitutional conventions when making a choice

It is generally considered that a Prime Minister must be, or be about to become, an MP. A peer has not served as premier since 1902. Sir Alec Douglas-Home was a peer upon his appointment as Prime Minister on 19 October 1963, but renounced his peerage four days later and was elected an MP at a by-election on 7 November. They must also be a Privy Counsellor, although an incoming Prime Minister usually already is (the last who was not was Ramsay MacDonald in January 1924).

The logistics

The arrangements for a change in Prime Minister are usually made by the Monarch and Prime Minister’s respective private secretaries. Buckingham Palace will call an incoming premier, telling them to “stand by” or summoning them to see the Monarch at a particular time. In their respective memoirs, Harold Wilson and James Callaghan both recall being asked when it would “be convenient” for them to meet the Monarch.

Following an election, a new premier will usually arrive at Buckingham Palace (or another royal residence) in their own car and leave in the Prime Minister’s official vehicle, although there are exceptions: in 2010 David Cameron was driven to the Palace in the Prime Ministerial Jaguar despite not yet being Prime Minister.

While most Prime Ministers resign or are appointed at Buckingham Palace, others have done so at Windsor. In 2022, Liz Truss kissed hands at Balmoral. Another exception was HH Asquith in 1908, who had to take a boat and train to Biarritz in France, where King Edward VII was on holiday. He is the only Prime Minister to have been appointed outside the UK.

The resignation

According to the Cabinet Manual, it is for the Prime Minister to judge the “appropriate time at which to resign, either from their individual position as Prime Minister or on behalf of the government”.

When a Prime Minister has resigned or lost an election, recent custom is for them to be photographed with their families at Downing Street before they drive to the Palace to tender their resignation to the Monarch. Some have also held a final session of Prime Minister’s Questions and made a speech outside Number 10 (“when the curtain falls,” said John Major in 1997, “it’s time to get off the stage”). Aerial cameras then follow the Prime Minister’s car as it drives up Whitehall, along the Mall and through the front gates of the Palace

The Monarch meets the departing Prime Minister and then their successor, often in quick succession (until 1963, a gap of a day or two was not uncommon). Recently it has become customary for a former Prime Minister’s partner and children to be invited to meet the Monarch immediately after their resignation.

A Prime Minister can resign in writing, which occurred in 1902, 1908 and 1963 because of ill health. “My letter of resignation was sent and delivered to Palace at 9.30am,” recorded Harold Macmillan in his diary on 18 October 1963. “So ended my premiership.”

The outgoing premier is often consulted regarding a successor, but his or her recommendation is not considered binding. To Byrum E. Carter, this preserves “the fiction” that the premier was “the King’s minister”. In any case, the choice will already have been made by the members of the governing political party, or by voters in a general election.

The appointment

When the outgoing premier has departed (in 2016, David Cameron’s car left the palace just 32 seconds before Theresa May’s entered), their successor will be greeted in the palace courtyard by an equerry and the King’s Private Secretary. They will wait in an antechamber to be briefed, most likely by the Lord Chamberlain, before entering the Monarch’s private apartments.

Only the Monarch and incoming premier are present during this audience. The Monarch appoints a Prime Minister under the royal prerogative, which means it does not have a statutory basis. The Monarch does so by asking the new Prime Minister to form an administration, to which they usually respond “yes”.

In October 1963, however, Sir Alec Douglas-Home asked for “leave to go away and see if I could form an administration”, as some in his party were reluctant to serve under him as Prime Minister. Having established that he could, Sir Alec was appointed premier at a second audience. In 2010, David Cameron was appointed Prime Minister but said he “wasn’t entirely sure what type of government it would be”.

When it is clear an individual can form a government, they are made Prime Minister, to quote Harold Wilson in 1964, “on the spot”. They also become First Lord of the Treasury from that moment, although the Oath of Office (as First Lord) is taken at a later meeting of the Privy Council. There are no seals of office as Prime Minister.

There is also no “kissing of hands”, although that phrase is used to describe the process. This used to occur but has fallen into abeyance. Instead, an incoming male premier will bow and shake hands with the Monarch, and a female premier will curtsy. In recent years this moment has been photographed for the media. There are no other formalities.

Having accepted this “commission” to form a government, there follows a brief exchange between the Monarch and their new Prime Minister. Gordon Brown recalled “a congenial and businesslike conversation about the work that lay ahead” with the late Queen Elizabeth II.

The new Prime Minister again shakes hands with the Monarch and bows or curtsies before being shown out by an equerry.

The appointment is published in the Court Circular and in a Downing Street press notice.

The departure

Some former Prime Ministers have returned to Downing Street despite no longer holding office. Neville Chamberlain did so in 1940 and, on 6 April 1955, Sir Winston Churchill dealt with government business before giving a farewell tea party for staff. In 1976 Harold Wilson went to Chequers after his resignation; in 1997 John Major watched cricket at the Oval and, in 2007, Tony Blair travelled to his Sedgefield constituency.

A newly appointed premier will be escorted out of Buckingham Palace (via the Ministers’ Staircase) by the Lord Chamberlain or the Monarch’s Private Secretary, who now addresses them as “Prime Minister”. As the Thatchers drove through the palace gates in 1979, “Denis noticed that this time the Guards saluted” his wife Margaret.

New Prime Ministers generally go to 10 Downing Street (which they inhabit by virtue of being First Lord of the Treasury) and make a speech. They announce their acceptance of the Monarch’s commission to form an administration and make a statement of intenta public statement of intent. Afterwards, a new Prime Minister traditionally enters Number 10 to applause from staff.

Further reading

The Privy Council: history, functions and membership

The Crown and the constitution

The royal prerogative and ministerial advice