Here's the first confirmed candidate to be Britain's next prime minister
Crabb reportedly declared his candidacy in an email to Tory MPs sent at 12:46 p.m on Tuesday, according to Politico, which first broke the story.
However on Wednesday morning, Crabb officially confirmed his candidacy, saying in a statement:
"First, we must unite. Just over a year ago, every Conservative MP was elected on a manifesto that committed us to holding a referendum. The campaign is now over."
"I want to lead a government that delivers on the expectations of the 17 million people who voted for Britain to leave the EU. We cannot allow this leadership election to be defined by divisive labels like 'Remainer' and 'Brexiteer'. The quicker we can focus on the future, the better chance we have to unite our party and the country."
Crabb, who is 43, is currently the Work and Pensions Secretary, having replaced Iain Duncan Smith in the role earlier in 2016 after Duncan Smith dramatically resigned his position due to criticisms of government policy.
Crabb will run jointly with business secretary Sajid Javid, who will be his number two. Javid is expected to become Chancellor of the Exchequer if the pair are successful. Speaking to BBC Radio 4 on Wednesday morning, Javid said: "Stephen has absolutely what it takes to lead this country to make it stronger."
While Crabb is the first candidate to declare, it is expected that he will soon be joined by former London mayor and prominent Leave campaigner Boris Johnson, home secretary Theresa May, health secretary Jeremy Hunt, and potentially energy minister Andrea Leadsom. Liam Fox is also thought to considering running for the leadership.
Prospective leaders must declare their candidacy by lunchtime on Thursday, and a new leader will be confirmed on September 2, it was confirmed following a meeting of the Tories' 1922 Committee on Monday. You can read more about how the leadership election works here.
As it stands, May is the favourite to win the election, marginally ahead of Johnson when it comes to betting odds. May is roughly 5/4 to be the new prime minister, while Johnson's odds are around 6/4. Earlier on Tuesday, a poll suggested that Conservative members currently back May ahead of Johnson.
The leadership election was triggered after prime minister David Cameron announced his resignation last Friday following the UK's vote to leave the European Union.