2.2 - Relative powers of the Commons and Lords

Commons confidence and supply

The government must retain the confidence of the elected House of Commons, not the approval of the House of Lords, to remain in office.

Confidence concerns whether MPs support the government continuing to govern. A Commons no-confidence vote can demonstrate that ministers have lost that support. Under constitutional convention, a government unable to regain confidence must resign or seek a dissolution and election. The monarch's role in appointing a prime minister does not mean the monarch substitutes a personal policy preference for Commons confidence. A Lords defeat cannot itself remove the government.

Distinguish an ordinary policy defeat from a loss of confidence. A government can lose a bill amendment while continuing to command enough MPs' support to hold office. Not every disagreement is automatically a no-confidence vote. The Fixed-term Parliaments Act's former statutory procedure was repealed in 2022; do not attach its old fourteen-day mechanism to every present defeat. The Commons Library's confidence briefing, checked 2 October 2026, explains the present constitutional relationship.

Supply means parliamentary authorisation of resources for government spending. Taxation and expenditure require the relevant legal authority, and the Commons has the decisive financial role. Without authorisation, ministers cannot treat their policy preferences as permission to raise taxes or spend unlimited public money. Thus confidence and supply describe two related sources of Commons control: government survival and funding. Confidence is principally a constitutional convention; financial authorisation is expressed through legislation and parliamentary financial procedure.

For example, the Conservatives and DUP made such an agreement on 26 June 2017. The DUP promised support on confidence and financial votes and specified Brexit and security legislation; other support was to be agreed case by case. This was different from a coalition with both parties holding ministerial offices. The published agreement is evidence of a political commitment, not a law creating the Commons' existing powers.

If you sit in 2027: Issue 3's glossary uses “confidence and supply” for the Commons' control over government survival and funding, and also for a support agreement. Issue 4, first assessed in June 2028, focuses its glossary on the agreement. Understand both meanings accurately: an agreement promises votes; it does not create the Commons' constitutional and financial authority.

Financial primacy and Money Bills

The Commons' exclusive financial position gives elected MPs the final authority over public taxation and spending.

Financial privilege is the Commons' special claim over those matters. Supply and taxation bills originate in the Commons. The Lords can debate financial policy, but cannot insist on overriding the Commons' financial decisions. Financial implications also arise in ordinary bills: a Lords amendment extending a benefit may increase expenditure. The Commons may accept an amendment where procedure permits and waive its privilege, or reject it on financial-privilege grounds. The existence of a cost does not mean the Lords is forbidden from discussing the issue. Erskine May's financial-privilege explanation sets out these distinctions.

A Money Bill is a narrower statutory category, certified by the Commons Speaker, whose contents concern only specified financial matters and incidental provisions. Not every bill that costs money is a Money Bill. Under the Parliament Act 1911, a qualifying Commons Money Bill sent to the Lords at least one month before the end of the session can receive Royal Assent without Lords consent if the Lords does not pass it without amendment within one month. The second chamber can consider the bill, but cannot use rejection to impose an indefinite financial veto. Parliament's guide to the Acts explains the special route.

Lords revision and scrutiny

The Lords normally has substantial opportunities to examine legislation even though its blocking power is restricted.