The disclosure comes as senior party figures told The Mail on Sunday that Mrs May had voted for ultra-Remainer Rory Stewart in Thursday’s ballot of MPs, which led to a landslide victory for Mr Johnson.
Mrs May, who has vowed to stay on as an MP after she leaves Downing Street next month, has suggested she would join forces with pro-Remain Ministers such as Chancellor Philip Hammond and Pensions Secretary Amber Rudd to try to stop Mr Johnson from leaving after the October 31 deadline ‘Deal or No Deal’.
No one ever looked this pleased to see Theresa! Pictured: Former Foreign Secretary Boris Johnson meets association activist to National Conservative Convention Hustings as part of his leadership campaign
The scale of Mr Johnson’s victory means that, barring a major Boris blow-up, the race has effectively turned into a battle for second place, with his vanquished opponents deciding whether to fight on or clamber aboard his bandwagon.
It is predicted that the Commons contest to whittle down the field of six to a final two will conclude as soon as Wednesday, after two more rounds of votes. The last two will then face an electorate of more than 160,000 Tory members, after a surge of new members who signed up ahead of the contest were deemed eligible to vote by party chiefs.
Last night Mr Johnson moved to scotch suggestions he wished to avoid a run-off, saying it was ‘full steam ahead to a contest’.
Britain’s Prime Minister Theresa May arrives at the Houses of Parliament in central London on Thursday June 13
Esther McVey, who came last with nine votes on Thursday, was the first former candidate to declare her intentions, saying that she would swing behind Mr Johnson and urging her eight supporters to do the same.
A source said: ‘Boris has told Esther that he will give his backing to blue-collar Conservative policies, such as the need to invest in the Midlands and North’.
Health Secretary Matt Hancock, who pulled out on Friday, was last night on the brink of declaring, with friends saying that he was wavering between backing Mr Johnson or Michael Gove – although most expect ambitious Hancock to plump for the frontrunner.
Last night Mr Johnson moved to scotch suggestions he wished to avoid a run-off, saying it was ‘full steam ahead to a contest’
‘Matt would be a moderating influence on the likely PM and help unify the party,’ the friend said.
In a further boost for Mr Johnson, it is expected that Mrs May’s closest Commons aide, Aberdeenshire MP Andrew Bowie, will endorse him to help unify the Scottish party around Mr Johnson’s banner. Some of the most intense soul-searching was going on in second-placed Jeremy Hunt’s team, with Ms Rudd – who until recently had been poised to form a blockbuster double act with Mr Johnson – angered by Mr Hunt’s recent hardline remarks on abortion.
Her views are understood to be shared by Defence Secretary Penny Mordaunt, who has also signed up to Mr Hunt’s campaign but warned she would not defend his stance that the legal time limit for a termination should be reduced from 24 weeks to 12.
Yesterday Home Secretary Sajid Javid made an impassioned plea to stay in the race, saying it was not just the ‘message that mattered, but the messenger too’.
The size of Mr Johnson’s victory has also concentrated minds in the party over his Brexit strategy, and in particular his pledge to leave the EU without a deal if Brussels refuses to make changes to the Withdrawal Agreement.
Boris Johnson, leadership candidate for Britain’s Conservative Prime Minister, leaves home in London, Britain, today
It was Mrs May’s failure to secure changes to the deal, and its subsequent rejection by MPs, which led to her downfall. But her allies say she has ‘not budged’ in her view that the UK should not leave the EU unless a deal has been struck and that to do otherwise would ‘jeopardise the integrity of the Union’.
One said: ‘She made little secret of the fact that she did not want Boris to succeed her, and if you study everything she has said it is clear where she now is on No Deal. The best hope is that Boris is bluffing as usual.’
Allies of the PM believe that she voted for Mr Stewart in order to ‘keep the race interesting’ despite claims in Westminster she was backing Jeremy Hunt. The Foreign Secretary’s 43 votes match 43 public declarations, meaning one of his supporters was being publicly misleading about who they voted for, or Mrs May – who has never publicly expressed her intentions – must have backed someone else.
Conservative party leadership contender Boris Johnson arriving for the Conservative National Convention meeting at the Park Plaza Riverbank Hotel, central London, today
Mr Stewart was one of Mrs May’s final appointments to her Cabinet and had been one of the most ferocious defenders of her Brussels deal. He has also said he would not seek major changes to Mrs May’s Withdrawal Agreement that has been comprehensively rejected by the Commons three times.
Instead Mr Stewart has said he would seek to ‘communicate’ the deal in a better fashion, and, like Mrs May, has vowed to avoid a No Deal scenario at all costs. A senior Tory told The Mail on Sunday: ‘At the end of the day Mrs May believes the only way to leave is with a deal and Rory is the only candidate really sticking to that.’
Another ally added: ‘No one has asked her but she values loyalty, and while he was quick out the traps in saying he wanted to run, Rory spent most of the year defending her.’