Theresa May was hit with a backlash today over Britain paying a Brexit “divorce bill” of up to £50 billion.

The Prime Minister was warned that agreeing to hand over the giant sum to Brussels risked damaging the Conservative party and the Government.

Britain and the EU were today closing in on a “divorce” settlement, reportedly of between £40-£49 billion, to allow talks to move on to a trade deal.

However, former chancellor Lord Lamont, who backed Brexit, said: “I’m in favour of a deal. But if the figure is a net figure after receipts that come back to us during a transitional period then it seems a very high price indeed.”

Leave Tory MPs also voiced concerns. Peter Bone said: “If the Government give billions away to the EU it will be very bad news for the Conservatives and the Government electorally. That’s how it translates in this country — at the ballot box.”

MP Steve Double said: “For me it seems high. It’s certainly at the very top end of what I would be willing to support but it depends on our future relationship.

“I would not support agreeing a figure of that size without knowing what the future trading relationship would be. It’s all very one-sided at the moment.”

Fellow MP Geoffrey Clifton-Brown said: “This figure would be more than our transport or defence budgets. I don’t think the public are going to like it very much. But if that is what the Government considers our liabilities are then we will have to pay it.”

Former Tory party chairman Lord Tebbit also believes the public will be surprised by the huge sum. “I don’t think they will react very nicely to it,” he said.

“But at the end of the day, provided we escape from the rule of an unelected government, it’s worth it.” Tory MP Bernard Jenkin said: “We pay nothing if there is no deal, and we are not committed to any exit payment unless we get a good deal.”

The “divorce settlement” is expected to be paid out over many years, despite Mrs May — on a visit to the Middle East — stating in January that “the days of Britain making vast contributions to the European Union every year will end”.

The Government, though, may never tell the public exactly how much the bill could rise to in the end.

Officials were reported as saying there was broad agreement on a framework for the UK to settle liabilities expected to total about £40-£49 billion. But former Ukip leader Nigel Farage said: “It’s a humiliating, abject surrender — and not in our national interest.”

Differences with Dublin over the border between Ireland and Northern Ireland could still block progress at the European Council summit on December 14-15.

EU lead negotiator Michel Barnier said today that the bloc is still “awaiting sufficient progress from London” on all three major divorce issues: citizens, money and the Irish border.

Mr Barnier said next month’s summit would only open talks on transition, with trade talks next year.