British Prime Minister Theresa May stepped up calls for Labour Party leader Jeremy Corbyn to agree to a cross-party deal to leave the European Union, following poor results for both parties in local elections on Thursday.
"To the leader of the opposition, I say this: Let's listen to what the voters said in the local elections and put our differences aside for a moment. Let's do a deal," she wrote in the Mail on Sunday newspaper.
Labour responded by saying any deal should be done quickly but accused May of leaking details of the compromise under discussion and jeopardising the talks.
The parties have been in negotiations for over a month to try to broker a Brexit deal that can secure majority support in parliament.
The talks with Labour are a last resort for May, whose party's deep divisions over Brexit have so far stopped her getting approval for an exit agreement, leaving the country in a prolonged political limbo.
Conservatives to offer new concessions to Labour, media reports say
The Sunday Times reported that the Conservatives would offer new concessions to Labour when talks restart on Tuesday, including a temporary customs union with the EU until a national election is due in June 2022.
"At that point, Labour could use their manifesto to argue for a softer Brexit if they wanted to and a new Conservative prime minister could argue for a harder Brexit," a source cited by the Sunday Times said.
Corbyn has made a permanent customs union with the EU a condition for supporting May's Brexit plans, while most Conservatives oppose a customs union as it would stop Britain from reaching its own trade deals with other countries.
The report on the terms of a possible compromise angered Corbyn's senior ally John McDonnell.
Asked if he trusted May, McDonnell said: "No, sorry. Not after this weekend when she's blown the confidentiality... I actually think she's jeopardised the negotiations for her own personal protection."
Nevertheless, McDonnell said talks would continue this week and if a deal could still be struck, it must be concluded quickly.
Even then, the parliamentary approval — required by law — is not straightforward.
Eurosceptic lawmaker John Redwood tweeted on Sunday that a cross-party agreement that amounted to staying in the bloc was "the last thing we need."
On the other side of the Brexit divide, the Observer newspaper reported that scores of Labour lawmakers had written to May and Corbyn to insist on a second Brexit referendum on any deal agreed.
"I think if they push forward with this it will be seen as a coalition of politicians against the people, and I think millions of people would give up on both Labour and the Conservatives," Brexit Party leader Nigel Farage said on Sunday.
A temporary customs union would also be likely to raise EU concerns that it could lead to customs checks on the border between eurozone member Ireland and the UK province of Northern Ireland if it later breaks down — something Ireland objects to strongly.