THE Government has been defeated in the House of Lords after peers voted to give MPs a veto over Theresa May’s final Brexit deal.

It’s the second time the unelected upper house has hampered the Tory Government’s plans to trigger Article 50, the formal process for leaving the EU.

Though, ultimately, it will only temporarily slow the Prime Minister down rather than derail the UK’s Brexit negotiations.

Peers supported a Labour-led amendment by 366 to 268.

Former Tory deputy prime minister, Michael Heseltine led a sizeable rebellion of Tory Lords and Ladies.

“Everyone in this house knows that we now face the most momentous peacetime decision of our time,” he said. “And this amendment secures in law the government’s commitment ... to ensure that Parliament is the ultimate custodian of our national sovereignty.

“It ensures that parliament has the critical role in determining the future that we will bequeath to generations of young people.”

Though May has indicated MPs will have a vote on the final Brexit deal, it is, effectively a “take it or leave it” choice.

If MPs reject the deal the Government manages to negotiate with the EU, then it means Theresa May will take the “cliff-edge” option of leaving Europe and the UK will have to take up with World Trade Organisation rules, which brings with it a nightmare of tariffs and of costly bureaucracy.

The Lords amendment gives Parliament the ability to tell the Government to try again, but ultimately keep Britain in the EU.

Arguing against the proposal, former Scottish secretary Michael Forsyth said: “These amendments are trying to tie down the Prime Minister. Tie her down by her hair, by her arms, by her legs, in every conceivable way in order to prevent her getting an agreement, and in order to prevent us leaving the European Union.”

The Brexit Bill now heads back to the House of Commons, and MPs will vote on the amendment, along with another guaranteeing the rights of EU citizens, which Lords passed last week.

Despite the best efforts of SNP and Lib Dem MPs and some Tories, the Commons, which has supremacy in Parliament, will likely scrap the Lords amendments.

The peers will then, likely, back down.

Earlier, the Government comfortably saw off a bid to give voters the final say on the Brexit deal.

The LibDem-led move to put the outcome of Brexit negotiations to a referendum was heavily defeated by 336 votes to 131.

Meanwhile, May has dismissed calls to hold a snap election.

Former Tory leader William Hague suggested that going to the country and getting a bigger Commons majority would make it easier to deliver a successful Brexit and quash calls for a new Scottish independence referendum.

Writing in a newspaper, Hague said: “We have a new Prime Minister and Cabinet facing the most complex challenges of modern times: Brexit negotiations, the Trump administration, the threat from Scottish nationalists, and many other issues.”

Hague, who know sits in the Lords, said May should take advantage of a Labour Party in its “worst condition since the early 1930s” and with “its least credible leader ever”.

No 10 said May has been “clear and consistent in her position: that she does not think there should be” an early general election, while another added: “It’s not going to happen.”