The prime minister is the head of the government of the United Kingdom.

By constitutional convention, the prime minister is the individual best placed to command the confidence (majority support) of the House of Commons – a description that generally aligns with the leader of the largest political party in the commons.

The holder of the office has ultimate power over, and responsibility for, all policies made and implemented by the government. The prime minister chairs the cabinet, sets the government’s policy direction and represents the UK on the world stage.

The title of “prime minister” and the office surrounding it are established by convention rather than statute (law). Originally, the term was used as a pejorative, intended to criticise a minister perceived to be exercising authority in an overly dominant or “prime” fashion. The man widely regarded as Britain’s first prime minister, Robert Walpole, himself vehemently rejected the label. Walpole denied that he held any such singular or pre-eminent position within the government.

The prime minister almost always holds the title of first lord of the Treasury. The last prime minister not to hold it was Lord Salisbury in 1902. The first lord’s official residence is 10 Downing Street, which is why the prime minister lives there.

The prime minister also holds the positions of minister for the civil service and minister for the union.

The current prime minister is Andy Burnham, who took office on 20 July 2026.

The appointment of the prime minister

The monarch, as head of state, invites the individual best able to command the confidence of the House of Commons to serve as prime minister and form a government.

This power was exercised by Queen Elizabeth II in appointing Liz Truss in September 2022, and subsequently by King Charles III in appointing Rishi Sunak in October 2022, Keir Starmer in July 2024 and Andy Burnham in July 2026. Technically, the monarch also reserves the right to unilaterally dismiss a prime minister; by convention, however, any action such as this would today be seen as constitutionally outrageous and illegitimate.

Changes of prime minister have historically been closely connected to the electoral cycle. However, since 1997, only two prime ministers (Gordon Brown and Rishi Sunak) have left office directly as a result of a general election defeat.

In other cases, prime ministers have resigned during periods of political turmoil, often after losing the confidence of their own party. In such circumstances, the monarch has appointed as prime minister the individual who emerged as the new party leader through an internal leadership contest, on the understanding that they are best placed to command the confidence of the House of Commons.

Historically, the monarch has not been constrained in exercising their prerogative power to select the prime minister. The convention that the prime minister is the MP serving as the leader of the largest party in the commons has evolved over time. In this way, the last prime minister to serve from the House of Lords was the Marquess of Salisbury (Robert Gascoyne-Cecil). Salisbury served as prime minister on three occasions from 1885 to January 1886, August 1886 to 1892, and 1895 to 1902.

The prime minister’s role and powers

The power of the prime minister is extensive but largely derived from constitutional convention rather than statute law.

Head of government

The prime minister, as the head of the government appointed by the monarch, appoints all other members of the government, including the cabinet. They chair cabinet meetings, set the agenda, and act as the final arbiter in any disputes between government departments.

Within cabinet, the prime minister is said to be primus inter pares. They are seen as the ultimate decision-making force in an otherwise collective body. This Latin phrase, meaning “first among equals”, signifies that while they are officially part of a collective decision-making body, the prime minister acts as the ultimate decision-making force, setting the agenda and serving as the final arbiter in disputes.

The prime minister’s principal power is arguably that of patronage (appointments). They have the ultimate responsibility for advising the monarch on the appointment of a vast range of senior public figures, including all members of their government.

The prime minister may also dismiss ministers. Patronage is a tool for a prime minister to build and ensure loyalty within their party.

The prominence of individual ministers, who may have their own power base in the party or parliament, can act as a check on prime ministerial power. The prime minister may not be politically strong enough to exercise their patronage powers (hiring and firing) to their fullest extent.

Parliamentary leader

The fusion of the legislative and executive branches under the British constitution means that the prime minister is a member of the commons and controls its agenda.

The prime minister sets the legislative agenda and instructs the government “whips”, party appointees responsible for maintaining discipline, to organise parliamentary business and secure sufficient support for government legislation in the House of Commons. The whips have many tactics at their disposal to ensure the completion of the government’s agenda.

The prime minister’s position in the commons also acts as a constraint on their powers. They are accountable to MPs and can only govern so long as they enjoy the confidence of the commons. Informally, this confidence is expressed on an almost daily basis when it comes to passing the government’s legislative agenda, which must achieve a majority in the commons.

Military and foreign policy power

The prime minister has ultimate responsibility for the deployment of the armed forces and for matters of national security. They oversee foreign policy, sign international treaties and represent the United Kingdom at major international summits like the G7 and G20.

The royal prerogative

A key source of the prime minister’s power is the royal prerogative.

The royal prerogative powers are the residue of powers that were once exercised personally by the monarch. These powers are now almost entirely exercised by the prime minister or by other ministers at the instruction of the prime minister. They form a key element of the UK’s unwritten constitution, providing the legal basis for a range of executive actions.

While these powers are extensive, they are not unlimited. They are constrained by constitutional conventions and acts of parliament. They can also be challenged in the courts.

The two key areas where the prime minister exercises the royal prerogative concerns parliament and foreign affairs.

Foreign affairs

The prime minister has the ultimate power to make and ratify treaties, to recognise foreign states and to conduct diplomacy. The power to declare war and deploy the armed forces overseas is also a prerogative power. It remains the case that the decision to use military force, as a matter of law or constitutionality, does not require the prior approval of parliament.

A convention, however, has evolved that the House of Commons should be given the opportunity to debate the decision before troops are committed to combat. There is a statutory check on the prerogative power to ratify treaties. The Constitutional Reform and Governance Act 2010 (CRAG) brought the so-called ‘Ponsonby Rule’ onto a statutory footing, requiring a 21-day period to give parliament the opportunity to scrutinise and potentially delay treaties.

Parliament

The monarch, on the advice of the prime minister, exercises the prerogative powers to summon a new parliament after a general election and to prorogue (suspend) parliament at the end of a session.

Following the passage of the Dissolution and Calling of Parliament Act 2022, which repealed the Fixed Term Parliaments Act 2011, the power to dissolve parliament ahead of an election was also returned to the royal prerogative.

The Fixed Term Parliaments Act 2011 set in legislation a default fixed election date for the dissolution of a parliament and the next election. An early dissolution needed to earn the support of a “supermajority” of two-thirds of MPs. The Dissolution and Calling of Parliament Act 2022 thereby revived the power of the monarch, on the advice of the prime minister, to dissolve and summon parliament.

How is the prime minister held accountable?

The prime minister, as a member of the House of Commons, is directly accountable to parliament. They are held to account through a series of formal mechanisms.

Prime minister’s questions (PMQs)

Most prominently, the prime minister is subjected to questions in the commons chamber every Wednesday for approximately 30 minutes during prime minister’s questions (PMQs). The prime minister answers questions from across the House.

The leader of the official opposition (the leader of the second largest party in the commons) is granted six questions. The leader of the third largest party is granted two questions.

The liaison committee

The House of Commons Liaison Committee is a so-called “super-committee” composed of the cross-party chairs of all other Commons select committees. It has a broad oversight role, but is best known for questioning the prime minister in extended evidence sessions held two or three times a year. These sessions can allow for more detailed and sustained scrutiny than is possible during PMQs.

Ministerial statements

The prime minister is expected to report to the House of Commons on major policy decisions, significant announcements and international developments. This is done through ministerial statements. After the statement has been delivered, MPs can question the prime minister directly on the details.

Is the prime minister an ‘elected dictator’?

“Elective dictatorship” is a pejorative phrase sometimes used to describe the United Kingdom’s system of government, especially when a governing party commands a strong majority in the House of Commons. It argues that the constitutional framework allows the government, led by the prime minister, to dominate parliament to such an extent that it can pass its laws with little effective restraint.

The government of the day has significant control over the business and timetable of the House of Commons.

Whipping in parliament tends to ensure a high degree of party loyalty. Government whips encourage and, where necessary, pressure their MPs to vote in line with the party’s official policy. Government whips may also encourage MPs to ask questions that shine a positive light on government policy, especially at prime minister’s questions. This tactic is referred to as “planting” a question. This discipline can ensure that a government – even one with a slim majority – turns its parliamentary party into a reliable voting bloc, making defeat on key legislation rare.

Significantly, the checks listed above (PMQs and the liaison committee) do not technically constrain the prime minister’s ability to legislate.

However, the prime minister’s power is constrained by the very nature of political debate and its expression through formal procedures.

Most prominently, a government can be defeated or forced to change policy by a large-scale rebellion from within its own ranks. The threat of such a rebellion can be a powerful check on ministerial plans. A large rebellion can drastically weaken a prime minister’s position and even lead to their downfall.

How much is the prime minister paid?

MPs who serve as ministers or hold specific parliamentary offices are entitled to an additional salary on top of their basic MP’s salary. However, the ministerial portion of these salaries has been voluntarily frozen by successive governments since 2015.

The prime minister’s salary is actually £169,344. This comprises the £93,904 MP salary and a frozen claimed ministerial salary of £75,440. Technically, the legal entitlement for the minister’s salary is £80,807.

The prime minister: notable traditions and conventions

Audience with the monarch

The prime minister has a weekly private audience with the monarch. This meeting allows the head of government to inform the head of state of the government’s business.

The audience is entirely confidential. The monarch remains politically neutral on all matters. However, they may see fit to “advise and warn” their prime minister where necessary.

10 Downing Street

10 Downing Street is the permanent London residence of the first lord of the Treasury (prime ministers).

Sir Robert Walpole, widely regarded as Britain’s first prime minister, moved into the house on 22 September 1735. The house was originally part of a terrace built in the 1680s by Sir George Downing. King George II offered it to Walpole in 1732 as a personal gift, in recognition of his service and role in securing the Hanoverian Succession. Walpole, the first lord of the Treasury, had effectively functioned as the head of the government since 1721.

But Walpole refused to accept the property as a personal gift. He requested that the king make the house available as an official residence for the office of the First Lord of the Treasury, rather than to him personally.

10 Downing Street was not immediately or universally adopted by Walpole’s successors. Many 18th and 19th century prime ministers preferred their own, more lavish London townhouses.

Between 1735 and 1902, only 16 out of 31 prime ministers actually lived in the building, which was often considered too small or modest. When Walpole left Downing Street in 1742, it would be over 20 years before another first lord of the Treasury, George Grenville, moved in.

It was only from the early 20th century that it became the undisputed residence of the head of the British government.

Today, the Prime Minister’s Office, based at 10 Downing Street, is staffed by a mix of civil servants and politically appointed special advisers who provide policy advice, manage communications and help direct the government’s strategic goals.

Additional resources

• GOV.UK – 10 Downing Street: https://www.gov.uk/government/organisations/prime-ministers-office-10-downing-street
• UK Parliament – Liaison Committee: https://committees.parliament.uk/committee/103/liaison-committee-commons