Role of Prime Minister

Role of the Prime Minister UK

Fig. 1 - Rishi Sunak addressing the nation in his first speech as British Prime Minister, 25 October 2022.

The Prime Minister is the most powerful political office in the UK and holds significant representative, legislative, and formal power. The Prime Minister is the head of the executive, the decision-making branch of government (one of three branches of government).

The Prime Minister is not the head of state in the UK, although they are granted many significant powers. The United Kingdom is a constitutional monarchy, with the monarch as the formal head of state. The monarch still performs a variety of ceremonial roles, although many of the powers it traditionally enjoyed have passed to the Prime Minister and others.

This form of power is known as 'royal prerogative', in which the Prime Minister is granted various significant functions such as government appointments and declaring war.

As head of state, the monarch does retain some significant roles, such as acting as an international diplomat, appointing Prime Ministers, and giving royal assent to new legislation. Nevertheless, they must remain impartial and will rarely prevent a bill from passing.

Roles and responsibilities of the Prime Minister

The Prime Minister has a range of key roles and functions which they perform.

Head of government and the majority party in the commons

The Prime Minister is the leader of the majority party in the houses of commons, normally coming to power after a general election. However, there is no direct election for the Prime Minister, and the individual can change mid-election term if they resign without an election.

As the head of government, the PM is responsible for policy and decision-making, operating as the central figure in the Houses of Parliament. The Prime Minister also has several other titles. The PM is the head of the Treasury and the Civil Service (First Lord of the Treasury and Minister for the Civil Service).¹ They are also the 'Minister for the Union', a formal role (created by former PM Boris Johnson) where the PM seeks to ensure parliament is representative of the entire UK.

Leading the cabinet and organising government

One core function of the Prime Minister's executive power is their control over the cabinet and government departments.

The Prime Minister can organise government departments, often renaming or creating new departments to address their legislative needs or mandate. The Prime Minister appoints the cabinet ministers who head each department. Cabinet appointments are a central function of the Prime Minister, allowing them to choose ministers who best fit the role or who support them politically.

In theory, the Prime Minister acts as the 'primus inter pares' (the first among equals), recognising the shared power of the cabinet. Nevertheless, the Prime Minister generally leads most decision-making, particularly on policy. The Prime Minister leads cabinet discussions and controls the agenda. Although the cabinet can vote on policy, decisions are usually made by the Prime Minister and agreed upon by consensus. Nevertheless, cabinet ministers do hold considerable authority over their departments.

Policymaking and agenda-setting

The Prime Minister leads the policy focus of the government and commons.

Fig. 2 - MPs sat in the House of Commons during a debate on Brexit in 2019.

They play a central role in setting the agenda in both the cabinet and the legislature. The Prime Minister's policy agenda is often presented through their party manifesto at General Elections, something that can be used to hold the PM to account.

Government appointments

The Prime Minister also holds significant sway over government appointments and patronage.

Cabinet appointments

The PM can appoint and remove ministers, often for political reasons (such as support, popularity, or mistakes). For more significant changes, the PM can instigate cabinet shuffles, where several members of the cabinet may be altered.

Civil service

The PM is the Minister for the Civil Service, giving them oversight over Civil Servants. Nevertheless, appointments may be delegated to individual ministers, who may play a role in vetting and deciding key civil service roles.

Honours and peerage

The Prime Minister can nominate individuals for a peerage, meaning that they will be granted a position in the House of Lords. In particular, each outgoing Prime Minister can provide honours suggestions.

National leadership

As the leader of the executive, the Prime Minister plays a strong leadership role throughout government. The PM mediates royal prerogative with the monarch and may meet with other significant leaders nationally.

The PM is also the country's figurehead and can make national addresses in times of crisis or need. During the COVID-19 pandemic, Boris Johnson led the UK through regular national press conferences.

Fig. 3 - Boris Johnson delivering a COVID-19 press conference in July 2020.

International affairs

The Prime Minister is an international representative for the UK. They participate in international summits such as COP and the G20 and represent the country in diplomatic relations.

The Prime Minister is also in charge of national security and may represent the country's military actions and interests.

Role of Prime Minister in parliament

The PM leads parliament as the leader of the majority party in the House of Commons. Prime Ministers may not always command a parliamentary majority, but they always lead their own party.

The Prime Minister represents the government and incumbent party, pushing forward key decisions and acting at the forefront of government policymaking. The PM can also make important decisions such as proroguing parliament (temporarily stopping a parliamentary session) and calling a snap election.

Prime Minister's Questions (PMQs)

Every Wednesday, Parliament holds PMQs for 30 minutes. PMQs play a central role in government accountability, enabling the Leader of the Opposition and MPs to put forward questions to the Prime Minister.² It provides a chance for MPs to enquire about the actions of the government, and for the PM to defend their decisions.

Role of the Deputy Prime Minister

The role of 'deputy' Prime Minister is not a formalised role like the Prime Minister, but can be created according to the will of the Prime Minister. The role has existed under several premierships, including John Prescott during Tony Blair's premiership, Nick Clegg with David Cameron, and most recently Dominic Raab with PM Rishi Sunak.

Rather than acting as a direct replacement for the Prime Minister, the deputy may support the PM in some duties. Most commonly, the Deputy Prime Minister may lead PMQs in a PM's absence.

Although the role may indicate the incumbent's preference for a future replacement if needed, it is an ad hoc role and succession is by no means guaranteed.

Role of President and Prime Minister

The UK Prime Minister is the highest political office in the UK, operating under a constitutional monarchy. Countries with a republican form of government (without a monarch) often have a President who is the head of state, and then a Prime Minister as head of government - although the President often still has strong legislative powers.

Fig. 4 - Prime Minister Rishi Sunak meeting President Volodymyr Zelenskyy of Ukraine, November 2022.

UK Prime Minister vs. US President