Boris Johnson’s Tory opponents began cranking up a campaign to stop him becoming Prime Minister within 24 hours of his announcement he would stand for the party leadership, it can be revealed today.

The ‘Stop Boris’ campaign swung into action in Westminster last night – amid warnings that some Tories could force a general election rather than give him the keys to Number 10.

Mr Johnson is the runaway favourite to succeed Theresa May as Tory leader following a coup by backbench MPs this week that will see her step aside this summer.

His hopes were boosted last night by a poll showing he is the Tory most likely to beat Labour.

The exclusive Survation poll for the Daily Mail put the former foreign secretary more than 20 points ahead of Sajid Javid, his nearest rival for Theresa May’s job.

But two ministers said opposition to the former foreign secretary is so strong that some would be prepared to vote against him if he tried to introduce a Queen's speech - sparking an election this summer.

The 'Stop Boris' campaign swung in to action in Westminster last night - amid warnings some Tory MPs could force an election rather than allow him to enter Downing Street and pursue a No Deal Brexit. He is pictured yesterday opening a school playground gym in Uxbridge

One said: ‘Boris cannot form a government, certainly not on a No Deal platform and probably not on any other. There are at least a dozen people on our side, me included, who would be prepared to vote against him on the Queen’s Speech.

‘Even with the DUP on board, that is the majority gone. Then we are straight into an election.’ Another minister said: ‘Boris is extremely popular with the members, but the situation is the opposite among his colleagues at Westminster.

‘He could obviously win a leadership election in the country but there is a real question mark about whether he can command a majority in Parliament.’

Mr Johnson was streets ahead of the others on 32 per cent. His closest rival was Home Secretary Mr Javid on 11 per cent. Foreign Secretary Jeremy Hunt and Work and Pensions Secretary Amber Rudd were next, both with 7 per cent

Conservative MP Phillip Lee issued a public warning that no Tory leader campaigning on a No Deal platform could hope to govern without an election.

Dr Lee, who is facing a deselection attempt in his Bracknell constituency after backing a second referendum, said: ‘Boris is not fit for purpose as prime minister, but this is not just about Boris the person.

‘If any leader tries to make No Deal official Conservative policy then the Government does not last – it is going to lose a confidence vote.’ Supporters of Mr Johnson insisted that he could reinvigorate a deflated Tory party, deliver Brexit and defeat Jeremy Corbyn. Leading Eurosceptic Jacob Rees-Mogg said: ‘Boris would win back voters because he would deliver Brexit.’

Nadine Dorries said: ‘Boris would shore up the Tory vote – he is the best placed candidate to beat Corbyn.’

'Election could let in Corbyn', warns health minister Matt Hancock Health Secretary Matt Hancock has warned a general election could allow Jeremy Corbyn into No. 10 and lead to Brexit being 'killed altogether'. Mr Hancock urged MPs to 'deliver Brexit and move forward' to also prevent Nigel Farage's Brexit Party getting any traction if the country went to the polls. Theresa May will present another version of her exit plan to MPs next month and there are fears an election could be called if it is rejected again to give her successor more of a mandate. He told the Daily Telegraph: 'A general election before we've delivered Brexit would be a disaster. People don't want it. I'm with Brenda from Bristol. We need to take responsibility for delivering on the referendum result.' He added: 'A general election before that [Brexit] not only risks Jeremy Corbyn but it risks killing Brexit altogether. We've got to deliver Brexit in this Parliament, then we can move forward.' Advertisement

The Survation poll showed he was also the candidate with the highest ratings on the question of who would make a good prime minister and on who would be a vote winner.

A YouGov poll for The Times yesterday found he was the first preference of 39 per cent of Tory members – far ahead of his nearest rival Dominic Raab on 13 per cent.

But, under the terms of the Tory leadership rules, he must first persuade his fellow MPs to rank him in the top two candidates whose names will go forward for election by the party’s 125,000 members.

The poll also said only 10 per cent of Remain-voting Tory members supported him, while 31 per cent believe he would be a 'poor leader'.

Meanwhile Health Secretary Matt Hancock has warned a general election could allow Jeremy Corbyn into No. 10 and lead to Brexit being 'killed altogether'.

Mr Hancock urged MPs to 'deliver Brexit and move forward' to also prevent Nigel Farage's Brexit Party getting any traction if the country went to the polls.

Theresa May will present another version of her exit plan to MPs next month and there are fears an election could be called if it is rejected again to give her successor more of a mandate.

He told the Daily Telegraph: 'A general election before we've delivered Brexit would be a disaster. People don't want it. I'm with Brenda from Bristol. We need to take responsibility for delivering on the referendum result.'

He added: 'A general election before that [Brexit] not only risks Jeremy Corbyn but it risks killing Brexit altogether. We've got to deliver Brexit in this Parliament, then we can move forward.'

The exclusive Survation poll for the Daily Mail put the former foreign secretary more than 20 points ahead of Sajid Javid, his nearest rival for Theresa May’s job

Environment Secretary Michael Gove, who torpedoed Mr Johnson’s 2016 campaign and is widely expected to stand again, yesterday said he would make his own leadership intentions known 'in due course'.

As Mrs May’s hopes of passing a Brexit deal were seriously damaged by the acrimonious collapse of cross-party talks with Labour:

Jeremy Corbyn pulled the plug saying it was impossible to negotiate with an ‘unstable’ government;

Business groups reacted with dismay, complaining about ‘six wasted weeks’;

The Prime Minister attended the low-key private launch of the Tory European election campaign;

She also drew up a ‘bucket list’ of policy announcements for her final weeks in office.

The detailed poll of more than 1,000 people, conducted yesterday, asked who was most likely to beat Labour under Mr Corbyn.

Mr Johnson was streets ahead of the others on 32 per cent. His closest rival was Home Secretary Mr Javid on 11 per cent. Foreign Secretary Jeremy Hunt and Work and Pensions Secretary Amber Rudd were next, both with 7 per cent.

In head-to-head contests, Mr Johnson also triumphed against every other candidate. He was 17 points ahead of Michael Gove and Dominic Raab, ten ahead of Mr Hunt and 19 ahead of Matt Hancock. Significantly, 20 per cent of Labour voters said Mr Johnson’s leadership would make them more likely to vote Tory.

Theresa May spoke at an EU election campaign event in Bristol today. She also drew up a ‘bucket list’ of policy announcements for her final weeks in office

However he also had the highest negative ratings: he was seen as likely to be a good prime minister by 32 per cent of the public, but bad by 45 per cent.

Asked if Mr Johnson’s leadership would make them more likely to vote Conservative, 28 per cent of those questioned said yes – the highest figure for any candidate. But 38 per cent said they would be less likely to vote Tory.

If there was a general election tomorrow, the poll showed the Tories on 27 per cent, five points behind Labour, with the Brexit Party on 13 per cent. But with Mr Johnson as leader, the parties were neck and neck on 24 per cent, with the Brexit Party on only 7 per cent.

On Brexit, the poll found that opinion has barely changed from the referendum result nearly three years ago, with 49 per cent wanting to leave the EU and 51 per cent to remain. But the survey suggested Mr Johnson is seen as much more likely than Mrs May to ‘make a success of Brexit’.

It confirmed the Conservatives were likely to sustain heavy losses at the hands of Nigel Farage’s Brexit Party in Thursday’s European Parliament elections. The Tories were in third place on 14 per cent behind the Brexit Party on 30 per cent and Labour on 24 per cent. The Lib Dems were on 12 per cent and Change UK in the doldrums on just 3 per cent.