He would immediately look to press ahead with a series of domestic policies addressing a number of issues Theresa May failed to make much progress on. They could include a new insurance system for social care, increased funding for schools and tax cuts for high earners. During the past six weeks of the Tory leadership contest, Mr Johnson has made spending pledges that could potentially cost more than £26billion.
READ MORE: When will the next Prime Minister be announced? What is the timetable?
That is equal to the estimated “fiscal headroom” Chancellor Philip Hammond has left in the public finances to fight off the effects of a no deal Brexit on the economy.
Those backing Mr Johnson told the Daily Telegraph he will proceed with key policies by borrowing to pay for them if that is what is ultimately needed.
“We are talking about a fiscal loosening of less than 1 per cent of total public spending,’ one aide said.
“It would do a lot to get things moving for the middle classes, to get them spending more money.’
Another added: “In order to honour Boris’s spending pledges, the next budget is going to have to put a temporary freeze on deficit reduction.
“Of course it is important to continue fixing the roof but there is going to have to be some flexibility there to give the economy the post-Brexit boost that it needs.”
Follow the live blog from Express.co.uk for the latest updates:
Tory leader news: Jeremy Hunt could still defeat Boris Johnson is what would be a massive upset
11.22am update: ‘She was very, very dignified’ Rory Stewart praises Theresa May after last Cabinet meeting
Rory Stewart has praised Theresa May after he left 10 downing Street following a Cabinet meeting chaired by the outgoing Prime Minister.
The International Development Secretary, who had been in the race to become Tory leader, has insisted he will not serve in a Boris Johnson-led Government.
Leaving Number 10, Mr Stewart said of Mrs May: “She was very, very dignified.”
11.16am update: Education Minister quits – minutes before Tory leader announcement
Anne Milton has become the latest Conservative MP to resign from the Government in opposition to a possible no deal Brexcit.
In her resignation letter to Theresa May, she says she has “grave concerns about leaving the EU without a deal”.
The Guildford MP says: “I believe strongly that parliament should continue to play a central role in approving a deal, and that we must leave the EU in a responsible manner.”
Ms Milton has spent 13 years on the Conservative front bench, and added in her letter: “In my view if we are to leave the EU it is essential we maintain a close relationship with our nearest neighbours and biggest trading partners and I will continue to support the government as it tries to find a way to achieve this.
“I had hoped we could have left the EU on 29 March, and regret that this was not possible.
“It has been an honour and privilege to serve in government for the last nine years.
“I am proud of what we have achieved, particularly my final role implementing the Apprenticeship Programme which will be vital for the country’s future after Brexit.
“I will continue to represent my constituents, but I believe I can do this most effectively from the backbenches.”
Tory leader: Will Jeremy Hunt be returning to 10 Downing Street as Prime Minister?
11.03am update: New Prime Minister timetable: When will May leave? What new PM’s first week will look like
Boris Johnson and Jeremy Hunt are awaiting the result of the Tory leadership election. So when will Theresa May leave – and what is the timetable for week one of the new Prime Minister?
11.45am: The new Prime Minister will be announced by the 1922 Committee.
The announcement will be broadcast live, which you can watch HERE.
Rest of the day: New PM finalises his choice for Cabinet. First speech is written and he’ll visit the Conservative Campaign Headquarters to thank the campaign team in person.
12pm: Theresa May faces her final Prime Minister’s Questions in the House of Commons.
1pm: Philip Hammond officially resigns as Chancellor to Mrs May and we can expect to see other soft Brexit supporters resigning around here too (assuming Mr Johnson wins).
2pm: New PM will meet with ministers in his new Commons office who he intends to sack.
3pm: Theresa May visits the Queen at Buckingham Palace and officially resigns as Prime Minister.
4pm: New PM visits the Queen at Buckingham Palace and is invited to form a Government.
5pm: New PM makes his first speech outside Number 10. He enters the building for the first time as Prime Minister.
Evening: New PM makes senior Cabinet appointments and holds meetings with senior civil servants.
He is given the nuclear codes and is updated on matters of national security.
He’ll write his “letters of last resort” to commanders of Trident-carrying submarines with instructions for what to do in the event of Britain and its Government being wiped out by a nuclear attack.
He’ll take congratulatory phone calls from world leaders.
Tory leader news: Boris Johnson was told he is ‘not fit to be Prime Minister’
11am update: Lib Dem in furious attack on Johnson – ‘He is not fit to be Prime Minister’
Jo Swinson has launched a scathing attack against Boris Johnson, raging ‘he only cares about himself’.
She told Sky News: “I frankly think the man is not fit to be prime minister.
“He only cares about Boris Johnson.
“In politics you get to know people in different parties and you disagree with them.
“But often you have the feeling that – although you have a disagreement – they’re genuinely trying to do what they think is right.
“They have the country’s best interests at heart, even though you’ve got a different judgment on what that is.
“I have to say, with Boris, I don’t feel that – I think he only cares about himself.
“That is what is so dangerous about him becoming Prime Minister.
“Because this is about him – and maybe to some extent the Conservative Party – when this should be about the national interest.”
10.20am update: Hunt win would be ‘biggest shock in the history of political betting’
Boris Johsnon is still the huge favourite to be the UK’s next Prime Minister, with odds of 1/100 on at some bookmakers.
Jeremy Hunt is now priced as high as 20/1.
Ladbrokes said a win for the Foreign Secretary would be “the biggest shock in the history of political betting”.
Tory leader news: Jeremy Hunt was in confident mood as he arrived at 10 Downing Street
10.14am update: New Lib Dem leader Swinson opens door for rival ministers to join her
Jo Swinson has claimed she has been involved in talks with MPs from other parties, including the Conservatives, about defecting.
Several Tory ministers will quit or have threatened to do so if Boris Johnson is named as the new Prime Minister because of his increasing no deal Brexit rhetoric.
Ms Swinson told BBC Radio 4’s Today programme: “Our door is absolutely open to people who share our values.
“I am talking to people in different parties, including Conservatives.
“There is a reason why thousands of people are joining the Liberal Democrats, when the Conservatives have gone off to the right and Labour have gone off to the left and people who want to see a better politics, a better alternative than the – frankly depressing – choice of Boris Johnson and Jeremy Corbyn, they can join us because there is a better way.”
10.09am update: Iran sends warning to Johnson as UK tensions intensify
The new Prime Minister will be tasked with delivering Brexit by October 31, but also managing the UK’s growing tensions with Iran.
Speaking in Nicaragua this morning, Iranian Foreign Minister Mohammad Javad Zarif said: “Starting a conflict is easy, ending it would be impossible.
“It’s important for everybody to realise, it’s important for Boris Johnson to understand, that Iran does not seek confrontation.”
9.56am update: Jeremy Hunt arrives at Downing Street for Cabinet meeting
The Tory leadership underdog has arrived at 10 Downing Street for what will be Theresa May’s last Cabinet meeting.
Mr Hunt is in buoyant mood this morning, and when asked how he is feeling ahead of the next Prime Minister announcement, he told reporters: “All to play for.”
Tory leader news: Boris Johnson or Jeremy Hunt will become the UK’s 73rd Prime Minister
9.50am update: Pound continues to fall ahead of Tory leadership announcement
Sterling slumped for a third day in a row ahead of this morning’s announcement of the UK’s next Prime Minister.
The British currency was trading at around half a cent lower versus the US dollar at just above $ 1.24.
Financial markets have become increasingly anxious about frontrunner Boris Johnson’s continued no deal Brexit rhetoric.
9.46am update: Rory Stewart repeats he would not serve under Johnson
International Development Secretary Rory Stewart has repeated his intention to quit if Boris Johnson is victorious in today’s vote.
He was arriving with other ministers, including Jeremy Hunt, Matt Hancock and Liz Truss for a Cabinet meeting at 10 Downing Street.
When asked if he would serve under Boris Johnson, Mr Stewart replied: “No.”
9.35am update: Nearly a dozen ministers could quit if Johnson becomes PM – Sky News Political Editor
Beth Rigby has predicted up to 10 current ministers could resign from the Cabinet if Boris Johnson is named as the UK’s next Prime Minister.
She tweeted: “What might Johnson cabinet look like? Big changeover coming. Watch for more resignations today.
“On my out list: Hammond, Guake, Stewart, Clark, Lidington, Perry, Noakes, Bradley, Wright, Brokenshire
“In list: Patel, Raab, Wallace, McVey, Fallon, Sharma (Buckland/Morgan?).”
Tory leader news: Boris Johnson is the huge favourite to become the UK’s next Prime Minister
9.28am update: Prominent MEP tells Johnson to continue with Northern Ireland-only backstop and call general election
Belgian MEP Philippe Lamberts, a member of the European Parliament’s Brexit steering group, warned Boris Johnson “will be confronting the exact same situation as Theresa May”.
He told BBC Radio 4’s Today: “Boris Johnson is known to want many things and often contradictory things like having your cake and eating it, he is on record saying that.
“So indeed he wants good relations with the European Union and he wants to be able to cut off all ties and not have the Irish backstop and all the rest of it.”
But the Green MEP suggested Mr Johnson could look to pass a Brexit deal with a Northern Ireland-only backstop, something which would lose the support of the DUP – who currently prop up the government – but could pick up support from elsewhere in Parliament.
He added: “If I were Boris Johnson I would do just that and then call for a general election which I think he could then win having delivered a form of Brexit.”
9.21am update: ‘Day Brexiteers took control’ BBC’s Kuenssberg says Boris backers believe ‘he can do it’
Political commentators believe that “brexiteers will take control of Government” as the Tory party awaits the announcement of who will succeed Theresa May as leader and Prime Minister.
As a Brexiteer that has always supported Britain’s exit from the union, Boris Johnson is prepared to walk away from the bloc without a deal.
Ahead of the results, BBC political editor Laura Kuenssberg said the vote could finally see “brexiteers take control of Government”.
She tweeted: “Boris Johnson who has dreamt of this job for years is about to find out if he is really up to it – some of his backers have pretty intense fixation on the power of his belief and conviction to inspire people in this nightmare scenario.”
9.10am update: ‘Let sunshine win the day’ Boris optimism can help Brussels shift towards Brexit deal – Sir Michael Fallon
The former Defence Secretary told BBC Radio 4’s Today programme: “Nobody is aiming for no-deal, that is not the strategy. We want a better deal, Parliament wants a better deal, and Boris Johnson has made clear throughout that he wants a better deal.
“But the way to get a better deal is to be very firm that that date is there in law.
“There are three months now before the end of October and it is perfectly possible, with plenty of goodwill on both sides, to improve the agreement so that Parliament does, in the end, support it.”
He added: “Let sunshine win the day. Boris is optimistic about this, he is ambitious about this. We have three months to get wording that Parliament will approve.
“I think you will find that a new government, a new mandate which Boris, I hope, will get this morning, a new focus, new ministers in charge, a fresh negotiating team – I think you will find that Brussels will not be unwilling to say ‘OK, what are the points that you need to satisfy Parliament on?’.”
8.57am update: Employment Minister calls for Tory unity or ‘risk Corbyn Government’
Alok Sharma, who is supporting Boris Johnson, has called for unity from within the Conservative Party from ministers returning to the back benches.
He warned they risk handing the key to 10 downing Street to Labour leader Jeremy Corbyn if this did not happen.
Mr Sharma told BBC Two’s Newsnight: “I hope what they will do is reflect on the fact that the new prime minister, if it is Boris, will actually have a mandate from the parliamentary party and from the membership.
“What we will do if we have disunity in the party is risk a Corbyn Government.”
Tory leader news: Chancellor Philip Hammond will quit if Boris Johnson becomes Prime Minister
8.45am update: Hunt tight-lipped on if he would serve under Johnson
Jeremy Hunt was giving little away just hours before the UK’s next Prime Minister is announced.
Asked if he thinks he has won, he replied: “Who knows?”
Quizzed on if he knows who has won, he said: “No, I don’t.”
Asked if he is feeling positive, he replied: “I’m feeling very positive, but who knows what’s going to happen?”
Mr Hunt also tight-lipped on whether he would serve under Boris Johnson, and said: “All to be seen. Let’s wait for the result.”
8.41am update: Gauke won’t vote against Johnson Government in motion of no confidence
Justice Secretary David Gauke, who will resign if Boris Johnson is elected as the UK’s next Prime Minister, has stresses he will not vote against a Tory Government in a motion of no confidence if Britain was heading for a no deal Brexit.
But he believes there are “parliamentary mechanisms” which could prevent the UK leaving the EU without an agreement, which would “not necessarily” involve bringing down an administration led by Mr Johnson.
When quizzed if he would vote in a motion of no confidence, Mr Gauke told BBC Radio 4’s Today: “I don’t think it will come to that. I think that there will be parliamentary mechanisms, if you like.
“There is a clear majority in the House of Commons that doesn’t want to leave the EU without a deal, I think that will become very clear in the autumn.”
He added: “Are there circumstances where there is a risk of a government losing a confidence motion? Yes, clearly there are circumstances where there is a risk that that might happen.
“I think that the new prime minister would be wise to avoid getting into those circumstances.”
Tory leader news: The lowdown on favourite Boris Johnson
8.35am update: Jeremy Hunt still hopeful as result announcement nears
The underdog in the Tory leadership race still believes he can overcome the odds and defeat Boris Johnson.
Mr Hunt arrived back at his residence after a morning run at 7.10am.
When asked how he felt about today, he said: “All to play for.”
8.30am update: Boris says free trade deal can finally break Brexit deadlock
Boris Johnson has said Britain could agree a free trade deal to leave the European Union that would finally break the Brexit deadlock.
He suggested various forms of technology could be used to avoid having to stick with the problematic Irish backstop, which has been central to MPs opposing the Brexit deal put before them and resoundingly voting it down in the House of Commons on three separate occasions.
Both Mr Johnson and leadership rival Jeremy Hunt have said the backstop needs to be removed from the much-criticised agreement Mrs May struck with the EU.
He wrote in his column for the Daily Telegraph: “There is abundant scope to find the solutions necessary – and they can and will be found, in the context of the Free Trade Agreement that we will negotiate with the EU, after we have left on October 31.
“We can come out of the EU on October 31, and yes, we certainly have the technology to do so. What we need now is the will and the drive.”