What is confidence and supply?

Confidence and supply is a deal in which a smaller party agrees to back a minority government on key votes. These are votes of confidence and supply, meaning the Budget and spending. In return it gets policy concessions or funding. Unlike a coalition, the smaller party does not join the government or take ministerial jobs.

Confidence votes decide whether a government survives. Supply votes approve the money it needs to function. If a minority government loses either, it is in serious trouble. A confidence and supply deal guarantees support on those votes, while leaving both parties free to disagree on other issues. Losing a supply vote would mean the government could not legally spend money, so these votes really matter.

The best-known recent example came after the 2017 general election. The Conservatives lost their majority and agreed a confidence and supply deal with Northern Ireland's Democratic Unionist Party. The DUP's 10 MPs backed the government on key votes, and Northern Ireland received about £1 billion of extra funding. The deal lasted until 2019. Critics said other regions lost out. The DUP gained real influence at Westminster.

Similar deals are common in devolved parliaments and in other countries such as Canada and New Zealand. They let a minority government function without the commitments of a full coalition. Critics say they can lead to one region or group gaining special treatment. Supporters say they give stability while keeping the smaller party independent. They also can collapse fast. They can also collapse quickly.