LEGISLATION to allow the UK to choose which bits of European Union law it keeps after Brexit must not be rushed through Parliament like the bill to authorise Theresa May to trigger exit negotiations, a parliamentary committee has said.

The House of Lords Constitution Committee said it recognised the “political imperatives” that lie behind the fast-tracking of the European Union (Notification of Withdrawal) Bill.

But it warned the accelerated timetable, with less time allowed between different stages in the Commons and Lords, should not set a precedent for the so-called Great Repeal Bill, which will transpose all EU law into UK law, giving Parliament the power to decide which bits to keep.

The EU (Notification of Withdrawal) Bill was tabled after the Supreme Court ruled last month the Prime Minister must get authority from MPs and peers before triggering Article 50 to begin Brexit negotiations.

It was first debated by MPs on January 31 before being fast-tracked through the Commons.

The chairman of the Lords Constitution Committee, former Scottish secretary Lord Lang of Monkton, said: “The European Union Withdrawal Bill is undeniably of significant constitutional importance.

“Usually we would be concerned about the fast- tracking of constitutional legislation, particularly when the justification for doing so depends on a political, rather than constitutional, deadline.

“However, we recognise the political imperatives that underlie this Bill. We have made clear, however, this should not set a precedent for future constitutional legislation.”

Ministers are considering a concession to peers, who are threatening to inflict a defeat on the Government over giving Parliament a “meaningful vote” on the final Brexit deal.

A Downing Street spokesman said: “We will bring forward a motion on a final agreement that will be approved by both Houses before it is concluded.”