THERESA May said both sides will have to compromise in cross-party Brexit talks with Labour as she faced a backlash over the negotiations with Jeremy Corbyn’s party.

Further talks are expected this week ahead of Wednesday’s European Council meeting. Labour’s key demand is for a customs union with Brussels in order to protect the flow of goods, but Brexiteers vehemently oppose anything that would restrict the UK’s ability to strike free trade deals through being bound by tariffs set by the EU.

In a video message filmed at her Chequers country retreat, May said: “There are lots of things on which I disagree with the Labour Party on policy issues.

“But on Brexit I think there are some things we agree on: ending free movement, ensuring we leave with a good deal, protecting jobs, protecting security.

“And so we are talking. Can we find a way through this that ensures that we can get a good deal and a deal agreed through Parliament?

“It’ll mean compromise on both sides but I believe that delivering Brexit is the most important thing for us.”

Tory European Research Group chairman Jacob Rees-Mogg repeated his call for the UK to be “the most difficult member possible” in the EU if it was “forced to remain in”.

“I don’t think the EU, in its jargon, has behaved towards us with sincere co-operation,” he told Sky News’ Sophy Ridge On Sunday. “I don’t think sincere co-operation could possibly include trying to break up the unity of a member state when it leaves the EU, and therefore I think we are no longer obliged to follow sincere co-operation in return.

“When the multi-annual financial framework comes forward, if we are still in, this is our one-in-seven year opportunity to veto the budget and to be really very difficult, and I hope that any British prime minister would take that opportunity.”

Rees-Mogg praised Boris Johnson, whose leadership prospects have been boosted by speculation about an alliance with Remain-leaning Cabinet minister Amber Rudd which has been dubbed “Bamber” by Westminster insiders.

“I think very highly of Boris Johnson, who managed to win in London twice in a Labour area – has a great connection with voters.

“He is a clear Eurosceptic but otherwise is very much in the middle of the Conservative Party. He is not particularly a factional character beyond the European issue and therefore I think could unite the party and win an election.”

Rees-Mogg said he also “thought highly of Amber Rudd” who was a person of “first-class capabilities”.