Newly-appointed Chancellor Nadhim Zahawi has thrown his hat into the ring to become the next Tory leader.
The former education secretary and vaccines minister joins his predecessor Rishi Sunak in running for the job.
He's become the second Cabinet minister to declare their ambition in the space of an hour.
Mr Zahawi becomes the third serving government minister to kick off their campaign for the leadership after Grant Shapps and Attorney General Suella Braverman declared their intentions to run.
Earlier, defence secretary Ben Wallace said that after “careful consideration” and discussion with colleagues and family, he would not stand to be party leader and the next prime minister.
Mr Shapps, Mr Sunak, and Ms Braverman, ex-minister Kemi Badenoch and senior Tory Tom Tugendhat have all launched their own leadership bids, with further announcements anticipated over the coming days.
Foreign Secretary Liz Truss is widely expected to stand and to confirm her leadership run on Monday, while other potential front-runners include trade minister Penny Mordaunt and former health secretaries Sajid Javid and Jeremy Hunt.
Launching his campaign, Mr Zahawi pledged to lower taxes for individuals, families and business, boost defence spending and continue with education reforms that he started in his previous role, PA reports.
Born in Iraq to a Kurdish family, the new Chancellor came to the UK as a nine-year-old when his parents fled the regime of Saddam Hussein.
Believed to be one of the richest politicians in the House of Commons, he helped found polling company YouGov after studying chemical engineering at University College London.
He has often said that his own personal backstory has deeply influenced his view of Britain and he recently spoke of the debt he owed poet Philip Larkin as he improved his English as a teenager.
He has had something of an eventual week after first being promoted to Chancellor following Mr Sunak’s resignation on Tuesday, then defending Mr Johnson during a gruelling broadcast round on Wednesday, before publicly calling for him to stand down come Thursday morning.
And in his bid for leader, Mr Zahawi said: “My aim is a simple one: to provide the opportunities that were afforded to my generation, to all Britons, whoever you are and wherever you come from. To steady the ship and to stabilise the economy.
“Thanks to Brexit, we are now a free nation. Let’s not just talk about the opportunities that follow, let’s take them.
“If a young boy, who came here aged 11 without a word of English, can serve at the highest levels of Her Majesty’s Government and run to be the next prime minister, anything is possible.”
He added that he wants to “focus on letting children be children, protecting them from damaging and inappropriate nonsense being forced on them by radical activists”.
It was reported on Saturday that Boris Johnson intends to stand down as Prime Minister on Monday in order to run again for Tory leader, but this suggestion was knocked down by a spokesperson for Mr Johnson as completely untrue and is against the rules.
Tory MP Mark Francois has said he believes at least 12 people will put their names forward for the leadership position.
“I haven’t yet decided who I am going to vote for," he told GB News.
“It looks like this is going to be the Grand National but without the fences, so we are probably heading for at least a dozen candidates at the moment.”
Ms Badenoch announced her campaign in The Times, with a plan for a smaller state and a government “focused on the essentials”.
She is backed by Lee Rowley, the MP for North East Derbyshire, and Tom Hunt, the MP for Ipswich.
Former minister Steve Baker has thrown his support behind Ms Braverman’s bid, despite previously saying he was seriously considering putting himself forward for the top job.
Those publicly backing Mr Sunak include Commons Leader Mark Spencer, former Tory Party co-chairman Oliver Dowden, former chief whip Mark Harper, ex-ministers Liam Fox and Andrew Murrison, and MPs Sir Bob Neill, Paul Maynard and Louie French.
Other potential contenders have also received endorsements from Tory ranks, despite not yet launching a bid of their own.
MPs Chloe Smith, Julian Knight and Jackie-Doyle Price have backed Ms Truss, while Gosport MP Dame Caroline Dinenage has declared her support for Ms Mordaunt, and former ministers Chris Philp and Rachel Maclean have said Mr Javid would be their choice for PM.
The leadership bids to date have coincided with some controversy over the appointment of new ministers to Mr Johnson’s caretaker Government.
Labour shadow minister Steve Reed lashed out at the Conservative Party after Sarah Dines, who reportedly asked an alleged victim of Chris Pincher if he was gay, was made parliamentary under-secretary of state jointly at the Home Office and the Ministry of Justice.
The absence of a clear front-runner in the leadership race has tempted a number of less-fancied contenders to step forward, with backbencher John Baron saying he will be “taking soundings” over the weekend.
Tory MP and newly-appointed minister Rehman Chishti also confirmed on Saturday he is “actively considering” running for the post.
As candidates have started to make their move, Tory MP Sir Charles Walker said it is incumbent on those running for leader that they “don’t knock lumps out of each other”.
Following elections to the executive of the backbench 1922 Committee on Monday, the new body will draw up a timetable for the leadership election.
