Labour and the SNP have agreed with other opposition parties not to back Boris Johnson’s demand for a snap election before the European Council meets on October 17.
The Prime Minister wants to take the country to the polls on October 15, but requires two-thirds of MPs to back him in Parliament to bring an election about.
He failed to achieve this in a Commons vote on Wednesday night but is planning to table the same motion again on Monday.
But opposition leaders have agreed to vote against or abstain once more, despite SNP Westminster leader Ian Blackford saying he is “desperate for an election”.
Opposition and rebel MPs passed a bill this week designed to block no-deal by seeking a further Brexit delay if necessary. It was passed by the House of Lords on Friday and is expected to become law on Monday.
However, the Prime Minister has yet to commit to obeying the law when it comes into effect, with opponents wary he may ignore it and try to force the UK out of the EU by October 31.
Blackford said: “It’s not just about our own party interests, it’s about our collective national interests.
“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 an extension to Article 50.”
But he did anticipate that an election would be successfully called “over the course of these weeks”.
A Lib Dem spokeswoman described the conference call between leader Jo Swinson, Jeremy Corbyn, Blackford, Liz Saville Roberts of Plaid Cymru and others as “constructive”.
She said: “We were all clear 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.
“As a group we will all vote against or abstain on Monday.”