Plans to create a supreme court have provoked a showdown between ministers and peers. BBC News Online explains the row.
What are the proposed reforms?
Final appeals in court cases are currently held by the law lords - a special committee of the House of Lords.
The government wants to create a new supreme court to do that job. It would operate completely separately from Parliament, with judges recommended by an independent appointments' board.
How would the Supreme Court work?
The 12 law lords would be removed from the House of Lords to become Justices of the Supreme Court. The new court would become the highest court of appeal for all legal cases in England, Wales and Northern Ireland, and for civil cases in Scotland.
The Supreme Court would also take over the powers of the judicial committee of the Privy Council to rule in devolution cases. In other words it will be the Supreme Court that resolves disputes about the authority of UK Parliament, Scottish Parliament and Welsh Assembly.
Future appointments to the Supreme Court will be made by the Secretary of State for Constitutional Affairs, from a shortlist of between two and five names. The shortlist will be drawn up by a commission consisting of the two most senior Supreme Court Justices, a member of the Judicial Appointments Commission and representatives of the Scottish and Northern Irish judiciary.
What happened on Monday?
Opponents of the plans voted to get the plans examined by a special select committee, saying more scrutiny was needed.
Ministers say the move was simply an attempt to delay - and effectively kill - the Bill.
What are the critics' gripes about the plans?
Lord Woolf, the most senior judge in England and Wales, says it would exchange a first class final appeals court for a "second class" supreme court.
Unlike the American supreme court, for example, it would not be able to strike out legislation.
The Conservatives say the government is trying to ram through massive constitutional change without consultation.
Other critics argue the current system works so why bother spending vast sums changing it.
The Liberal Democrats are generally supportive of the idea, although they worry about the way judges for the new court will be chosen.
Has that opposition persuaded the government to drop the plan?
Far from it. Ministers say they will press on with the proposals. To maintain public trust, they say, there has to be complete separation between politicians who make the law and judges who interpret it.
So what happens now?
No decision has yet been announced, but there are a range of options available, including dropping the plans or setting a time limit on the select committee's work.
But Leader of the Commons Peter Hain said at the weekend he favoured pressing on and overriding House of Lords opposition by using the Parliament Act to force through the plans next year.
That is a rare and controversial step - it has only ever been done six times.