BORIS Johnson’s troubles continued to mount last night as opposition parties threw his elections plans into disarray and he was embroiled in a sexism row.

Capping a dire week for the Prime Minister, Labour, the SNP, LibDems and Plaid Cymru united to deny him his preferred election date of October 15 in order to avoid a no-deal Brexit.

The move means the Brexit deadline is likely to be delayed to 2020, with an election in late November or December.

A new poll suggested Mr Johnson’s lead over Labour’s Jeremy Corbyn would be obliterated in such circumstances.

It also emerged that Mr Johnson last month referred to David Cameron as a “girly swot” in an official document censored by Downing Street before it was used in a court case.

The Prime Minister’s jeering reference to his predecessor was in a handwritten note about his plan to shut down Westminster for five weeks. Mr Johnson also called Mr Corbyn a “big girl’s blouse” in the Commons this week.

The note was supplied to campaigners trying to overturn the prorogation at the High Court in London and at the Court of Session in Edinburgh. Both courts released redacted versions on Thursday.

However Sky News published an unredacted version showing the Prime Minister wrote: “The whole September session [at Westminster] is a rigmarole introduced by girly swot Cameron to show the public their MPs are earning their crust.”

LibDem leader Jo Swinson tweeted: “First it was ‘big girl’s blouse’ and now it’s ‘girly swot’. Boris Johnson thinks being a woman is a weakness. He’s going to find out it isn’t.”

Labour MP Yvette Cooper added: “Good grief. The Prime Minister of Great Britain thinks he’s still back at Eton - 'girly swot,' 'big girl’s blouse' - what century is he in if the word 'girl' is one of his staple insults?”

There also reports that Mr Johnson’s first Brexit proposals on Ireland had flopped badly in Brussels.

However Mr Johnson, who suffered a series of Commons defeats and saw his brother Jo quit as an MP this week over Brexit, did have some good news, as the High Court in London said his decision to prorogue parliament was lawful.

The Court of Session also refused to freeze prorogation, allowing it to go ahead as soon as Monday.

Mr Johnson said the opposition had made an “extraordinary political mistake” by not backing a mid-October election, and so he would get a deal with the EU rather than ask for a delay.

But the parties were adamant they would deny him the two-thirds majority needed for an election in a vote on Monday, just as they did this week.

The move is designed to force the PM to delay Brexit until at least January 31.

Emergency legislation compelling Mr Johnson to ask the EU for an extension if MPs have not passed a deal by October 19 passed the Lords last night.

It is expected to receive Royal Assent and become law on Monday.

The development coincided with an ICM poll showing Mr Johnson would lose his poll lead over Labour if he failed to hit his “do or die” deadline for leaving the EU because support for the Brexit party would double from 9 to 18 percent.

While Mr Johnson would beat Mr Corbyn by 37% to 30% in an October election, a delay to November would see Labour and the Tories tied on 28%.

Nicola Sturgeon said an election was now a question of when not if, but Mr Johnson “mustn’t be allowed to dictate the timing as a device to avoid scrutiny and force through a ‘no deal’ Brexit”.

SNP Westminster leader Ian Blackford added: “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.”

Plaid Cymru’s Westminster leader Liz Saville Roberts said: “We need to make sure that we get past 31 October, and an extension to Article 50. Boris is broken. We have an opportunity to bring down Boris, to break Boris, and to bring down Brexit – and we must take that.”

At the High Court, businesswoman Gina Miller had her bid to stop prorogation rejected, meaning an appeal to the UK Supreme Court.

At the Court of Session, three judges refused to grant campaigners led by SNP MP Joanna Cherry QC interim interdict against prorogation while they considered its legality ahead of a full decision on Wednesday. The Lord President Lord Carloway

said the case involved “extremely difficult issues”.

On Wednesday, Lord Doherty rejected the campaigners’ case, agreeing with the UK Government that it was a political matter, not one for the courts.