Former foreign secretary Boris Johnson says it would be “absurd” to hold a vote on the PM’s Brexit deal before attempting further talks with the EU.

Writing in the Daily Telegraph, the leading Brexiteer says: “There is an EU summit this week. It is not too late to get real change to the backstop.”

The backstop is a contingency plan for the Irish border, but has proved a sticking point in getting a final deal.

The PM’s plan is expected to be voted on for a third time in the coming days.

However, Chancellor Philip Hammond said it would only return to the Commons this week if it had support from many previously rebelling Tories and from the 10 MPs from the Democratic Unionist Party.

But DUP MLA Jim Wells told BBC Radio 4’s Today programme the party still had a “huge difficulty” with the existing backstop arrangements.

He said: “We could find ourselves locked in there forever in effect – and once you get in, you can never get out.

“We have to have a mechanism to escape the backstop.”

Negotiations with the DUP, whose MPs prop up the Tory government, are expected to continue on Monday, although Downing Street said a formal meeting was not scheduled.

‘Hardcore irreconcilables’

The Prime Minister would need 75 MPs to switch their support, exactly the number of Conservatives who voted against her deal.

But Jill Rutter, programme director at the Institute for Government, told the Today programme that there were about 20 “hardcore irreconcilables” in the European Research Group (ERG).

She said: “The Prime Minister can obviously offset those a bit if she brings the Democratic Unionists on board.”

Q&A: The Irish border Brexit backstop

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No Brexit deal vote ‘without DUP support’

Last week, MPs rejected Theresa May’s deal again – this time by 149 votes – and then backed plans to rule out leaving the EU without a deal.

They also voted in favour of an extension to the process – either until 30 June if Mrs May’s deal is supported before 20 March, or a longer one that could include taking part in European elections if MPs reject her plan for a third time.

But legally the UK is still due to leave the EU on 29 March.

All 27 EU member states would have to agree to an extension – and the countries’ leaders are expected to discuss it at a summit on Thursday. Not too late to change PM’s deal – Johnson

Meanwhile, Labour leader Jeremy Corbyn will have a series of meetings with other Westminster leaders and some influential backbenchers in an effort to find a cross-party compromise.