How the UK is governed

The House of Commons has 650 members, each elected from a single constituency by first past the post — the candidate with the most votes wins, regardless of whether they have a majority. Government is formed by whoever can command the confidence of the Commons, which in practice means the largest party or a coalition.

The House of Lords has around 800 members and no elected component. It consists of life peers appointed by the monarch on the Prime Minister's advice, a residual group of hereditary peers, and 26 Church of England bishops. Its powers were curtailed by the Parliament Acts of 1911 and 1949: it cannot block money bills at all, and it can delay other legislation for roughly a year rather than veto it.

By the Salisbury convention, the Lords does not block legislation that was in the governing party's election manifesto. That is convention, not law — which is precisely the pattern the whole constitution follows.

The Lords' real function is revision. It scrutinises legislation in detail, often improves it, and frequently forces the Commons to think again through 'ping-pong' — amendments passing back and forth. It is also where much genuine expertise sits, which is the standard defence of an otherwise indefensible arrangement.

Each of the 650 constituencies elects one MP by simple plurality. There is no threshold, no second round and no proportional adjustment. The system reliably produces two consequences.

First, it manufactures majorities. A party can win a substantial Commons majority on well under half the national vote, because votes are distributed unevenly. Second, it heavily penalises parties whose support is spread thinly and rewards those whose support is geographically concentrated — which is why nationalist parties can win many seats on modest national vote shares while UK-wide minor parties win few.

A 2011 referendum on replacing first past the post with the alternative vote was defeated by roughly two to one. The devolved legislatures use different systems: Scotland and Wales use an additional member system, and Northern Ireland uses single transferable vote, which is why coalition and minority government are far more normal there.

Voting is not compulsory. Turnout at recent UK general elections has run in the region of 60 per cent, well below countries with compulsory voting. Photo ID has been required to vote in person in Great Britain since May 2023 under the Elections Act 2022; Northern Ireland has required it since 2003.

King Charles III is head of state. The powers exercised in his name — appointing the Prime Minister, giving royal assent to legislation, dissolving Parliament, making treaties, declaring war — are prerogative powers, and they are exercised on ministerial advice in every ordinary case.

Royal assent has not been refused since 1708. The monarch appoints as Prime Minister whoever can command the confidence of the Commons, which is normally obvious. The weekly audience with the Prime Minister is private and, by convention, entirely confidential.

The genuinely open constitutional question is what happens when the ordinary case does not apply — a hung parliament with no obvious government, or advice that would be plainly improper. The 2019 prorogation case, in which the Supreme Court held that advice to prorogue Parliament for five weeks was unlawful and the prorogation void, was the first modern test and established that prerogative advice is justiciable.

Support for the monarchy remains majority but has softened, particularly among younger age groups. There is no organised constitutional pathway to a republic and no mainstream party proposing one.

A bill is introduced in either House, usually the Commons for government bills. First reading is formal. Second reading debates the principle. Committee stage examines it clause by clause. Report stage allows further amendment. Third reading passes it.

It then repeats the process in the other House. Where the two disagree, amendments pass back and forth — 'ping-pong' — until one gives way. Under the Parliament Acts the Commons can ultimately force through most legislation the Lords rejects, though this is rare.

Royal assent makes it an Act. Commencement is separate: many Acts come into force in stages by statutory instrument, sometimes years later, which is why 'the law has changed' and 'the new rule applies to you' are frequently different dates.

An enormous volume of law is made not by Acts but by secondary legislation — statutory instruments made under powers in an Act. Several thousand are made each year, with far less scrutiny than primary legislation, and this is a long-standing constitutional complaint.

The Scottish Parliament, Senedd Cymru and Northern Ireland Assembly hold legislative power over devolved matters — health, education, housing, planning, transport, the environment, and in Scotland and Northern Ireland most of the justice system. Scotland also sets income tax rates on earned income.

Devolution is asymmetric and reversible in theory: the UK Parliament remains sovereign and could legislate to abolish any devolved body. The Sewel convention says Westminster will not normally legislate on devolved matters without the consent of the relevant legislature, but the Supreme Court has confirmed that this is a political convention rather than a legally enforceable rule.

England has no devolved legislature. Instead it has an evolving patchwork of combined authorities and directly elected mayors covering roughly half the population, with powers over transport, skills and housing that vary by deal.

Local government sits beneath all of this: councils responsible for social care, waste, planning, libraries, schools admissions and local roads, funded by council tax, business rates and central grant. Structures differ — unitary authorities, two-tier county and district arrangements, London boroughs — and the money is chronically tight, with several councils having issued section 114 notices in recent years.