Tory leadership contest: Michael Gove and Andrea Leadsom will challenge Boris Johnson

Justice Secretary Michael Gove, in a dramatic turn of events in the Conservative Party leadership contest, has announced his decision to run for the top job. Gove was expected to throw his support behind Boris Johnson after the pair successfully campaigned for Vote Leave at the EU referendum.

But now the former journalists will compete with each other to become David Cameron's successor as Tory party leader, and therefore prime minister.

"I have repeatedly said that I do not want to be prime minister. That has always been my view. But events since last Thursday have weighed heavily with me," Gove said on 30 June.

"I respect and admire all the candidates running for the leadership. In particular, I wanted to help build a team behind Boris Johnson so that a politician who argued for leaving the European Union could lead us to a better future. But I have come, reluctantly, to the conclusion that Boris cannot provide the leadership or build the team for the task ahead.

"I have, therefore, decided to put my name forward for the leadership. I want there to be an open and positive debate about the path the country will now take. Whatever the verdict of that debate I will respect it."

Andrea Leadsom, the former city minister and fellow Vote Leave campaigner, has also launched a bid for the Tory leadership. She declared she wants to "make the most of the Brexit opportunities", in a post on Twitter. The moves turn the Conservative leadership contest on its head since Johnson and Home Secretary Theresa May, who has also launched her campaign today, were the bookies' favourites for the post.

Work and Pensions Secretary Stephen Crabb yesterday launched his campaign. The 43-year-old, who was born in Scotland but brought up in Wales by his single mother, has the support of Business Secretary Sajid Javid and will run on a platform of "a plan for unity and opportunity".

Elsewhere, former defence secretary Dr Liam Fox is expected to put his name in the hat, while Education Secretary Nicky Morgan and Health Secretary Jeremy Hunt have hinted that they might run.

If there are more than two candidates after nominations close at noon tonight, Conservatives MPs will vote them down in consecutive rounds. The two candidates will then face off in a vote by the party membership of more than 150,000.

UPDATE: Boris Johnson has ruled himself out form the race