The British parliament’s upper house backed an amendment to Prime Minister Theresa May’s bill to trigger formal Brexit talks, insisting on votes in both houses of parliament before an agreement is finalized with the European Union.
The unelected House of Lords voted 366 to 268 on Tuesday for the Labour-led cross-party amendment to the bill to trigger two years of formal Brexit negotiations.
The vote created a second extra hurdle for May after her government was defeated on an earlier amendment to the bill to protect the rights of EU citizens living in Britain.
She must now return the bill to parliament’s main house, the Commons.
May has promised to trigger Article 50 of the Lisbon Treaty, which sets the rules for a nation negotiating its exit from the EU, by the end of March.
Senior Labour members of the Lords have said they do not plan to block passage of the bill and will defer to the Commons if it overturns the amendments.
But some analysts have speculated that pro-EU rebels in May’s Conservative party could now shift their support away from the government when the bill returns to the Commons, which is expected next week.
David Davis, May’s Brexit minister, told British media the government was disappointed with Tuesday’s vote and will seek to overturn the amendments in the Commons.
Tuesday’s amendment requires parliamentary approval for the “outcome of negotiations with the European Union.”
It says that May cannot conclude a Brexit agreement with the European Union without the approval of both houses of parliament and that British lawmakers must vote on any agreement before a vote by the European Parliament.
In a vote to amend the bill last week, the Lords said the government must protect the rights of 3 million EU citizens residing in Britain.
The European Union (Notification of Withdrawal) Bill was sent to the upper house for consideration after passing through the Commons, where elected lawmakers approved it unamended with a clear majority.
If the Commons refuses to accept the changes, the bill will go back and forth between the two houses in what is known as a “parliamentary ping pong” until they are in agreement.
This could delay passage of the bill, but May and members of her cabinet have insisted that they remain on track to trigger Article 50 by the end of the month.