How the UK Cabinet Works: The Prime Minister's Inner Circle

Every Tuesday morning, around 20 senior politicians gather in the Cabinet Room at 10 Downing Street to make some of the most consequential decisions in British public life. They are the Cabinet, the Prime Minister's inner circle, and between them they run the entire machinery of the UK government. But what does the Cabinet actually do, who gets to sit in it, and how much power does it really have in an age when Prime Ministers increasingly govern through a tight circle of advisers? Here is how the Cabinet works, and why it still matters.

What the Cabinet Is

The Cabinet is the committee of senior ministers who collectively decide government policy. Each Cabinet minister typically runs a major government department — the Treasury, the Home Office, the Foreign Office, and so on — and is accountable to Parliament for that department's work.

The Cabinet has no fixed size. As of mid-2026, it has around 22 full members, though this varies by Prime Minister. Some Prime Ministers prefer a smaller, tighter Cabinet; others include more ministers to balance party factions or reward loyalty.

The Cabinet meets weekly, usually on Tuesday mornings, in the Cabinet Room at Number 10. Meetings are chaired by the Prime Minister, and the discussions are confidential. No minutes are published, though the Cabinet Secretary (the UK's most senior civil servant) takes notes and circulates a summary to ministers.

Who Sits in the Cabinet

Cabinet membership is entirely at the Prime Minister's discretion. There are no fixed rules about who must be included, though certain posts are almost always Cabinet-level:

• Chancellor of the Exchequer — runs the Treasury and sets the Budget
• Home Secretary — responsible for policing, immigration, and national security
• Foreign Secretary — leads UK diplomacy and foreign policy
• Defence Secretary — oversees the armed forces
• Health Secretary — runs the NHS
• Education Secretary — responsible for schools and universities
• Justice Secretary and Lord Chancellor — runs the courts and prisons

Other ministers are included based on the Prime Minister's priorities. Recent Cabinets have included ministers for levelling up, net zero, and Brexit, reflecting the government's focus at the time.

The Leader of the House of Commons and the Leader of the House of Lords usually sit in Cabinet, managing the government's legislative programme. The Chief Whip (who enforces party discipline among MPs) often attends but is not always a full member.

Some ministers attend Cabinet but are not full members — they are invited for specific items on the agenda. This allows the Prime Minister to keep the core group small while still consulting widely.

What the Cabinet Does

In theory, the Cabinet is the ultimate decision-making body in government. In practice, most decisions are made elsewhere — in Cabinet committees, by individual ministers, or by the Prime Minister and their advisers — and the Cabinet is informed rather than consulted.

Weekly meetings

Cabinet meetings last around an hour. The agenda is controlled by the Prime Minister, and discussions are often brief. Ministers report on their departments, the Prime Minister sets out priorities, and the Cabinet is asked to endorse decisions that have already been agreed in principle.

Votes are rare. The Prime Minister will usually gauge the mood of the room and declare a consensus. If a minister strongly disagrees, they are expected to raise it privately with the Prime Minister, not argue in Cabinet.

Cabinet committees

Much of the real work happens in Cabinet committees, smaller groups of ministers who meet to discuss specific policy areas (economy, national security, social policy, etc.). Decisions made in committee are binding, and the full Cabinet is simply informed of the outcome.

This system allows the government to make decisions quickly without requiring the full Cabinet to debate every issue. But it also means that power is concentrated in the hands of a few ministers, and backbench MPs (and even some Cabinet ministers) can be left out of the loop.

Collective responsibility

The most important rule governing the Cabinet is collective responsibility. Once the Cabinet (or a Cabinet committee) has made a decision, all ministers must publicly support it, even if they privately disagreed. If a minister cannot support a decision, they must resign.

This principle maintains a united front and prevents the government from appearing divided. It also means that ministers cannot distance themselves from unpopular policies — if the Cabinet decided it, they all own it.

Collective responsibility was suspended during the 2016 EU referendum, when ministers were allowed to campaign on opposite sides. This was highly unusual and reflected the depth of division within the Conservative Party over Brexit.

The Prime Minister's Power

The Prime Minister is not just the chair of the Cabinet — they are its dominant figure. The PM has several sources of power that make them far stronger than any individual minister:

Appointment and dismissal

The Prime Minister appoints all Cabinet ministers and can dismiss them at will. This power of patronage ensures loyalty. Ministers know that their careers depend on the PM's favour, which limits dissent.

A Cabinet reshuffle — when the PM moves ministers between jobs or sacks them — is one of the most visible displays of prime ministerial power. Reshuffles are used to reward allies, punish rivals, and refresh the government's image.

Control of the agenda

The Prime Minister decides what the Cabinet discusses and in what order. Issues the PM does not want to debate can be kept off the agenda or dealt with in a small committee instead.

The Prime Minister's Office

The PM is supported by a large team of advisers, civil servants, and political aides in Number 10. This gives the PM their own power base, independent of Cabinet ministers. In recent decades, Number 10 has grown in size and influence, centralising decision-making and reducing the Cabinet's role.

Public authority

The Prime Minister is the public face of the government. They lead at Prime Minister's Questions, represent the UK abroad, and set the tone for the government's message. This gives them a platform that individual ministers cannot match.

The Decline of Cabinet Government

Political scientists often talk about the decline of Cabinet government — the idea that the Cabinet as a collective body has lost power to the Prime Minister and their advisers.

Several factors have driven this shift:

• Presidentialism — Prime Ministers increasingly govern like presidents, with a large personal staff and a focus on direct communication with the public, bypassing Cabinet.
• 24-hour media — The need for rapid responses to breaking news means decisions are made by the PM and a small team, not by the full Cabinet.
• Complexity — Modern government is too complex for the full Cabinet to debate every issue. Decisions are delegated to committees or individual ministers.
• Dominance of Number 10 — The Prime Minister's Office has grown in size and power, with special advisers (SPADs) often wielding more influence than Cabinet ministers.

Margaret Thatcher, Tony Blair, and Boris Johnson were all accused of sidelining the Cabinet and governing through a small inner circle. By contrast, Theresa May's premiership showed the risks of a weak Prime Minister: her Cabinet was divided, and she struggled to impose her authority, leading to policy paralysis over Brexit.

When the Cabinet Pushes Back

Cabinet revolts are rare, but they happen. In 1990, Margaret Thatcher was forced to resign after losing the support of her Cabinet over Europe and the poll tax. In 2018, several ministers resigned from Theresa May's Cabinet over her Brexit strategy, weakening her government.

The threat of mass resignations is one of the few checks on a Prime Minister's power. If enough senior ministers resign, the government can collapse. But this requires coordination and courage, and most ministers are reluctant to give up their jobs.

Cabinet vs. Shadow Cabinet

The opposition party also has a Shadow Cabinet, a team of senior MPs who shadow government ministers and hold them to account. The Shadow Cabinet does not make government policy, but it sets out the opposition's alternative and prepares for power.

The Leader of the Opposition appoints the Shadow Cabinet, and the same principles of collective responsibility apply. Shadow ministers who break ranks can be sacked, as Jeremy Corbyn demonstrated in 2016 when he dismissed several frontbenchers who defied him.

The Bottom Line

The UK Cabinet is the Prime Minister's senior team of around 20–25 ministers, each running a major government department. It meets weekly to discuss and agree on policy, though most decisions are made in smaller committees or by the Prime Minister and their advisers. Cabinet collective responsibility requires all ministers to publicly support Cabinet decisions or resign, maintaining a united front. The Prime Minister appoints and dismisses Cabinet ministers, controls the agenda, and dominates the government through the power of Number 10, making them far stronger than any individual minister. Cabinet government has declined in recent decades, with power increasingly concentrated in the hands of the Prime Minister and their inner circle. The Cabinet remains important as a symbol of collective decision-making and as a potential check on prime ministerial power, but its role in day-to-day government is smaller than it once was.