Liz Truss will outline her move to become Prime Minister with a promise to “raise the bar in Conservative way” and reduce taxes.
The foreign secretary has the backing of Boris Johnson’s remaining supporters in the Tory leadership race to choose his successor.
Ms Truss’ supporters have been accused of campaigning to damage Mr Sunac’s chances in the contest, criticizing the former chancellor’s “economically damaging” policies.
In a campaign speech on Thursday, Ms Truss will detail her economic plan, which includes reversing April’s national insurance rate hike, cutting corporate tax and introducing supply-side reforms.
She is expected to say: “My mission is to make our country a nation of aspiration where every child, every person has the best opportunity to succeed.
“I have a plan to make the UK a high-growth economy through a bold reform proposal.”
The South West Norfolk MP also cites her education at a northern comprehensive school where she saw children “failing” because of “low expectations”.
“On my watch, they will never fail again.
“Everyone in our great country should be born with equal opportunities and know that the city they were born in has opportunities.”
“My mission in politics is to give every child, every person, the best opportunity to succeed, and that their success in life depends solely on their hard work and talents, not on their background or where they come from.”
Despite her loyalty to Johnson, Ms Truss kept her powder dry as the Tory top brass turned against the mortally wounded prime minister last week, although she cut short an overseas trip to Indonesia to return to Westminster when he announced his resignation.
She confirmed long-held expectations that she would throw her hat into an already crowded ring on Sunday.
The 46-year-old has made little secret of her leadership ambitions, making a series of high-profile speeches and photos in which she appeared to impersonate the late Prime Minister Margaret Thatcher.
The former Remainer’s hard line on Ukraine, who has become an ardent supporter of leaving the EU, insisting that Russian troops must be pushed out of the country, and threats to tear up parts of the Northern Ireland Protocol with the EU sit well with parts of the party.
After Wednesday’s vote, a spokeswoman for Ms Truss said she “has the experience to deliver the benefits of Brexit from day one, grow our economy and support working families”.
Chief Secretary to the Treasury Simon Clarke urged his fellow Tory MPs to rally around her “free market vision”.
In her speech, Ms Truss will talk about her experience in many Whitehall departments and her aim to unite the party.
“I am ready to be the prime minister on the first day. I can lead, make tough decisions and get to the point,” she is expected to say.
“The British people are calling for a united and modern Conservative Govt ready with the courage of his convictions to fulfill his promises.’