Theresa May will appeal for a show of unity from her warring MPs as she seeks to avoid a series of damaging Commons defeats on the Government’s centrepiece Brexit legislation.

The EU (Withdrawal) Bill returns to the Commons on Tuesday with ministers seeking to overturn a raft of amendments by the House of Lords intended to keep Britain close to the EU after Brexit.

However, they face a revolt by pro-EU Tory MPs determined to retain as many of the changes as possible in the legislation.

In what is likely to be a highly-charged appearance before the backbench 1922 Committee on Monday, the Prime Minister will remind her MPs they have a duty to deliver on the referendum vote to leave the EU.

She will make the point that while the bill itself may be a largely technical measure, the way that they vote in the division lobbies on Tuesday and Wednesday will send an important signal to the country.

“The purpose of the EU Withdrawal Bill is simple – it is putting EU legislation into law to ensure a smooth and orderly transition as we leave,” she is expected to tell them.

“But the message we send to the country through our votes this week is important. We must be clear that we are united as a party in our determination to deliver on the decision made by the British people.

“They want us to deliver on Brexit and build a brighter future for Britain as we take back control of our money, our laws and our borders.”

Despite depending on the votes of the 10 DUP MPs for her precarious Commons majority, there were signs of cautious optimism among ministers that they would get the numbers to see off the revolt.

Brexit
Former chancellor Ken Clarke is urging Tory rebels to hold their nerve (PA)

Some pro-EU Tories were reported to be backing away amid fears Mrs May could be fatally damaged by defeat, opening the way for a hardline Brexiteer to take over at the top of the party.

However, ministers were said to be taking nothing for granted with whips continuing to talk to MPs over the weekend – conversations that were expected to continue into the week.

Veteran former chancellor Kenneth Clarke urged the rebels to hold their nerve, arguing that if they succeeded they would strengthen Mrs May’s hand against the Brexit hardliners in the Cabinet.

He dismissed claims that defeat for the Government would lead to a general election potentially opening the door for Jeremy Corbyn to take power.

“Nobody in the House of Commons wants a general election. Most Labour MPs are as terrified of the idea of a Corbyn government as I am,” he told the BBC One Sunday Politics programme.

“What we need to do is to rescue the Prime Minister from this terrible treatment she is getting from key members of her Cabinet.”

The Government is thought to be most vulnerable on two amendments – one on the customs union and the other giving Parliament a decisive say over what happens next if it rejects a final Brexit deal.

The votes follow another bruising week for Mrs May over Brexit which saw David Davis reportedly threaten to resign unless there were changes to the Government’s latest “backstop” proposal to avoid a hard border between Northern Ireland and the Republic if there is no overall deal.

It then emerged Boris Johnson had privately suggested Donald Trump would make a better job of the Brexit negotiations than Mrs May was doing while the EU’s chief negotiator Michel Barnier rejected key elements of the “backstop” plan.

With Mr Davis in Brussels on Monday for the latest round of negotiations with Mr Barnier, the Cabinet Office Minister – and Mrs May’s de facto deputy – David Lidington denied the talks were in trouble.

“This is a negotiation,” he told BBC One’s The Andrew Marr Show. “I am expecting the talks to move forward. I am not expecting a meltdown.”