The Commonwealth of Britain Bill was a bill first introduced in the House of Commons in 1991 by Tony Benn,^[1] then a Labour Member of Parliament (MP). It was seconded by the future Leader of the Labour Party, Jeremy Corbyn.

The Bill proposed abolishing the British monarchy, with the United Kingdom becoming a "democratic, federal and secular Commonwealth of Britain", or in effect a republic with a codified constitution. It was introduced by Benn a number of times until Benn's retirement in 2001, but never achieved a second reading. Under the Bill:

• The monarchy would be abolished and the constitutional status of the Crown ended;
• The Church of England would be disestablished;
• The head of state would be a president, elected by a joint sitting of both Houses of the Commonwealth Parliament;
• The functions of the royal prerogative would be transferred to Parliament;
• The Privy Council would be abolished, and replaced by a Council of State;
• The House of Lords would be replaced by an elected House of the People, with equal representation of men and women;
• The House of Commons would similarly have equal representation of men and women;
• England, Scotland and Wales would have their own devolved National Parliaments with responsibility for devolved matters as agreed;
• County Court judges and magistrates would be elected; and
• British jurisdiction over Northern Ireland would be ended.
• The judiciary would be reformed and a National Legal Service would be created.
• The Constitution would be codified and an amendment process established.
• The voting age would be lowered from 18 to 16.
• MPs and other officials would swear oaths to the Constitution, not the Crown.^[2]