AN alliance has been formed by opposition parties at Westminster to scupper Boris Johnson’s plan to hold a General Election in the middle of next month amid fears he could put off the date in a ploy to force through a Halloween No-Deal Brexit.

The Prime Minister wants polling day to be October 15, ahead of a European Council summit on October 17 and 18. But under the Fixed Term Parliaments Act, to hold any snap election he needs to get a motion passed in the Commons by a two-thirds majority.

He failed to secure the necessary 434 votes on Wednesday night when MPs voted on a government motion to have the election then and wants to have a second attempt on Monday.

But following a meeting yesterday, Labour, the SNP, the LibDems and Plaid Cymru agreed they will vote against the Government or abstain in Monday’s vote, denying Johnson’s wish.

READ MORE: Boris Johnson Brexit cases to be tried in UK Supreme Court

The SNP’s Westminster leader Ian 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. We have to keep the pressure on Boris Johnson.”

Writing on Twitter, Nicola Sturgeon said: “An early General Election is now a question of ‘when’ not ‘if’ – but Johnson mustn’t be allowed to dictate the timing as a device to avoid scrutiny and force through a ‘no deal’ Brexit.

“The SNP relishes prospect of an election. But while our party interest might be served by voting for an election now, it is in the wider public interest to deny a PM threatening to defy the law any ability to cut and run in his own interests. We’ll act in the public interest.

“And when the election does come – as it soon will – @theSNP will put Scotland’s opposition to Brexit and our right to choose our own future as an independent nation at the very heart of the contest.”

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.”

And a LibDem spokeswoman said that the group was clear that it was “not going to let Boris Johnson cut and run”.

She said: “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.”

READ MORE: Boris Johnson claims there is 'no reason' for indyref2

Liz Saville Roberts, Plaid Cymru’s Westminster leader, said there was an “opportunity to bring down Boris” and “we should take that”.

Making the case for an election to take place on October 15, ahead of the Brussels summit on 17 and 18 October, Johnson argues a Tory win would allow the Government to force the EU to axe the backstop from the withdrawal agreement and deliver Brexit by 31 October. But the EU have insisted they will not remove the backstop and say they have yet to see any alternative proposals to it from Johnson.

Meanwhile, a Bill designed to prevent No Deal progressed through the Lords yesterday and is expected to get Royal Assent on Monday. It requires a delay to Brexit beyond October 31 unless a deal is approved or Parliament agrees to leaving the EU without one by October 19.

Johnson has insisted that he will not ask the EU for a new extension, saying he would rather “be dead in a ditch”. He has also said resigning as PM if he did not get a Brexit deal was “not a hypothesis” he would be willing to contemplate.