UK PM receives Lords blow for a second time

Prime Minister Theresa May suffered her second defeat in a week over Brexit Tuesday when the House of Lords voted to give parliament the final say on how Britain leaves the European Union.

Peers voted by 366 to 268 to amend the bill empowering May to trigger Article 50 of the EU's Lisbon Treaty -- the formal notification of Brexit, which she has promised to issue by the end of March.

She remains confident she will meet that deadline, but the defeat is a setback -- as well as a taster of the domestic opposition she could face in the coming months of complex EU negotiations.

The amendment would give parliament the power to reject the final Brexit deal agreed with the EU -- a move critics said was akin to a "veto" which would bind the government's hand in negotiations.

Lawmakers would still be constrained by the strict Article 50 timetable, which means Britain will leave the EU after two years whether it has a deal or not.

The defeat comes after the Lords voted last week to include in the bill guarantees for more than three million European citizens living in Britain after Brexit.

Brexit minister David Davis said the result was disappointing", and accused some in the Lords of seeking to "frustrate" the process of leaving the EU.

"It is the government's intention to ensure that does not happen. We will now aim to overturn these amendments in the House of Commons," he said.

The bill is expected to return on March 13 to the elected lower chamber, where May's Conservatives have a slim majority.