Crown-in-Parliament (sometimes written Queen-in-Parliament or King-in-Parliament, depending on the reigning monarch) is the formal expression of legislative sovereignty in the United Kingdom. Under the doctrine of parliamentary sovereignty famously articulated by A. V. Dicey in Introduction to the Study of the Law of the Constitution (1885), the Crown-in-Parliament can make or unmake any law, and no court or other body can override its enactments.
The concept reflects the tripartite structure of the Westminster legislature:
- The Monarch, who grants Royal Assent to bills.
- The House of Lords, the appointed and partly hereditary upper chamber.
- The House of Commons, the elected lower chamber.
A bill becomes an Act of Parliament only once all three elements have agreed (or, under the Parliament Acts 1911 and 1949, once the Commons has overridden the Lords in specified circumstances and the monarch assents). Royal Assent has not been refused since Queen Anne declined assent to the Scottish Militia Bill in 1708, making the monarch's role a formality in modern practice, though constitutionally essential.
The phrase distinguishes the Crown acting in its legislative capacity from the Crown acting in its executive capacity (ministers exercising prerogative powers) or judicial capacity (historically, the Crown as the fount of justice). It also underpins the enacting formula used in most UK statutes: "Be it enacted by the King's [or Queen's] most Excellent Majesty, by and with the advice and consent of the Lords Spiritual and Temporal, and Commons, in this present Parliament assembled, and by the authority of the same..."
The doctrine has been complicated, though not displaced, by EU membership (1973–2020), devolution to Scotland, Wales, and Northern Ireland, and the Human Rights Act 1998. In R (Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5, the Supreme Court reaffirmed that only the Crown-in-Parliament, not ministers using prerogative, could trigger withdrawal from the EU treaties.
Example
In 2017, the UK Supreme Court ruled in *Miller* that the government could not invoke Article 50 by royal prerogative alone; an Act of the Crown-in-Parliament was required, leading to the European Union (Notification of Withdrawal) Act 2017.
Frequently asked questions
In practice, yes. Royal Assent has not been refused since 1708 (Queen Anne, Scottish Militia Bill), but it remains a legally necessary step for a bill to become an Act.
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