Video report by ITV Political Correspondent Libby Wiener
Environment Secretary Michael Gove has officially entered the race to be the next Prime Minister, as the fight for the Tory crown showed signs of turning increasingly bitter.
The prominent Brexiteer Mr Gove is joining an already crowded field after Foreign Secretary Jeremy Hunt and ex-Cabinet ministers Dominic Raab and Andrea Leadsom threw their hats into the ring.
Mr Gove confirmed he is standing in Conservative leadership race on Sunday morning and told reporters outside his home: "I can confirm that I will be putting my name forward to be prime minister of this country.
"I believe that I'm ready to unite the Conservative and Unionist Party, ready to deliver Brexit, and ready to lead this great country."
As the Tory battle for Downing Street intensifies, Mr Gove’s intervention is likely to cause concern to current front-runner Boris Johnson.
A spectacular fall out between the two former allies in the 2016 leadership contest helped destroy both men’s chances of the top job.
Mr Gove is posing as a self-styled “unity candidate”.
Asked if he thinks he can beat Boris Johnson, Mr Gove said: "I'm entering this contest because I want to put forward a positive set of ideas about how we can bring our country together.
"I believe I'm ready to unite this country and ready to unite the Conservative and Unionist Party, and I'm looking forward to a contest of ideas."
Ms Leadsom revealed her plan to run as Conservative leader in the Sunday papers and said she believes she is the "decisive and compassionate leader" who can "reunite our great country."
Speaking to reporters outside her home on Sunday: "My absolute core is being a decisive person who gets things done but also a compassionate person who can see the need to reunite our country."
Chancellor Philip Hammond, who isn't running, said he might not be able to support a Tory Prime Minister who backs a No-Deal Brexit.
He said on the Andrew Marr show: "A Prime Minister who ignores Parliament cannot expect to survive very long."
"I have never voted against the Conservative whip, unlike many of my colleagues," he added.
"And I don't want to have to start now contemplating such a course of action so I hope - despite the pressures of a campaign, and I do understand the pressures of the campaign trail - that the serious candidates in this contest will focus on a strategy for building compromised solutions."
Mr Hunt was one of the first people to announce his leadership bid and believes his business credentials would help resolve Brexit.
He told The Sunday Times: "If I was prime minister, I’d be the first prime minister in living memory who has been an entrepreneur by background.
“Doing deals is my bread and butter as someone who has set up their own business.”
The Foreign Secretary's emphasis on his entrepreneurial past is being seen as swipe at Mr Johnson who reportedly once said “f* business” in relation to Brexit.
The rapidly expanding race is already heating up, as International Development Secretary Rory Stewart launched a strongly-worded attack on Mr Johnson.
Mr Stewart said he would refuse to serve in a government led by Mr Johnson and appeared to compare the ex-foreign secretary to Pinocchio.
He was scathing about Mr Johnson’s no deal stance, insisting that such a position was “damaging and dishonest”.
Meanwhile, both Mr Raab and Mrs Leadsom said they would also be prepared to order a no-deal Brexit in October if necessary.
Mr Raab told the Mail on Sunday he would prefer to leave the EU with a deal, but said the UK must “calmly demonstrate unflinching resolve to leave in October – at the latest”.
Mrs Leadsom, whose resignation helped trigger Mrs May’s dramatic resignation statement, told The Sunday Times that if elected PM, the UK would quit the EU in October with or without a deal.
She said: “To succeed in a negotiation you have to be prepared to walk away.”
Health Secretary Matt Hancock has also thrown his hat into the ring and said he was running for leader because the party needed to look to the future and attract younger voters.
Mr Hancock said he would take a different approach to try and get Commons support for a Brexit deal than the one Theresa May used.
He said: “She didn’t start by levelling with people about the trade-offs.
“I think it is much, much easier to bring people together behind a proposal if you are straightforward in advance.”
Chief Secretary to the Treasury Liz Truss said she would not stand for the leadership.
She told the Sunday Telegraph she would back a contender who supported Leave in the 2016 referendum.
Labour has said it will trigger a Commons no-confidence vote in the new prime minister when they take office.
The new Tory leader looks set to take over as prime minister at the end of July after Mrs May finally laid out a timetable for her exit from Downing Street.
The timetable for the contest will see nominations close in the week of June 10, with MPs involved in a series of votes to whittle down what is set to be a crowded field to a final two contenders.
Tory party members will then decide who wins the run-off.