UK opposition parties have agreed not to back Boris Johnson’s demand for a general election before the EU summit in mid-October.
Labour, the Lib Dems, the SNP and Plaid Cymru say they will vote against the government or abstain in Monday’s vote on whether to hold a snap poll.
The SNP’s Ian Blackford said they wanted to make sure the UK did not “crash out” in a no-deal Brexit.
But the PM said the parties were making an “extraordinary political mistake”.
Mr Johnson wants an election to take place on 15 October, ahead of the Brussels summit on 17 and 18 October.
He argues that this will allow the government to “get on” with delivering Brexit by 31 October.
During the past week the prime minister has suffered a series of defeats over Brexit in Parliament, expelled 21 of his own MPs for rebelling and seen his younger brother, Jo Johnson, resign from government.
Mr Johnson’s decision to prorogue – suspend – Parliament next week ahead of a Queen’s Speech on 14 October is also being challenged in the courts in Scotland and Northern Ireland.
Campaigner Gina Miller has lost a judicial review she brought to London’s High Court over the prorogation. However, permission has been granted for the case to be heard in the UK Supreme Court on 17 September.
Meanwhile, a bill designed to prevent a no-deal Brexit is expected to finish its progress through the House of Lords on Friday.
Following the meeting of opposition parties on Friday, a Labour Party spokesman said: “Jeremy Corbyn hosted a positive conference call with other opposition party leaders this morning.
“They discussed advancing efforts to prevent a damaging no-deal Brexit and hold a general election once that is secured.”
SNP Westminster leader Mr Blackford said he was “desperate for an election”, but it could not be until an extension to Article 50 – the process by which the UK is leaving the EU – had been secured.
“It’s not just about our own party interests, it’s about our collective national interests,” he said.
“So we are prepared to work with others to make sure we get the timing right, but the timing right on the basis of securing that extension to Article 50.”
He added: “We have to keep the pressure on Boris Johnson.”
Liz Saville Roberts, Plaid Cymru’s Westminster leader, said there was an “opportunity to bring down Boris” and “we should take that”.
And a Lib Dem spokeswoman said the group was clear that “we are not going to let Boris Johnson cut and run”.
“The Liberal Democrat position for a while now is that we won’t vote for a general election until we have an extension agreed with the EU. I think the others are coming round to that,” she said.
“As a group we will all vote against or abstain on Monday.”
But Mr Johnson said he would go to Brussels on 17 October and agree a deal so the UK can come out of the EU on 31 October.
He said resigning as prime minister if he did not get a Brexit deal by then was “not a hypothesis” he would be willing to contemplate.
Mr Johnson also said he was “perplexed” by the decision of opposition parties to “run away” from an election.
“All I see is Corbyn and the SNP clubbing together to try and lock us into the EU when it’s time to get this thing done,” he said.
“It’s the most sensational paradox – never in history has the opposition party been given the chance for election and has turned it down.”
