The Tory leadership race has narrowed to 10 candidates in the contest to replace Theresa May, the joint acting chairman of the backbench 1922 Committee Dame Cheryl Gillan has said.

The battle finally began officially as party grandees announced the full list of contenders who had mustered the required eight backers needed to stand.

Boris Johnson, Jeremy Hunt, Michael Gove, Dominic Raab, Sajid Javid, Matt Hancock were all in formally confirmed as candidates, the backbench 1922 Committee announced.

Esther McVey, Andrea Leadsom, Mark Harper and Rory Stewart were also in the contest.

Sam Gyimah, who was the only Tory runner to call for a second referendum, announced he is pulling out of the race because there has “not been enough time to build sufficient support”.

In the past, candidates needed just two MPs supporting them, but the 1922 Committee decided to change the rules earlier this month in an effort to speed up the contest.

Under another rule change, contenders now need to win the backing of at least 16 MPs in the first ballot this Thursday and then 32 colleagues in the second round next week.

All 313 Conservative MPs will vote in a series of private Commons ballots to reduce the shortlist to just two names.

The final two will then be on the ballot paper and stage a series of hustings around the country before 160,000 Tory members cast their votes. A winner, and new prime minister, will be announced in July.

Earlier, four contenders launched their campaigns with speeches and press conferences at various locations in Westminster.

Jeremy Hunt, Michael Gove, Dominic Raab and Matt Hancock all claimed they were the one with the best policies to deliver Brexit and restore the party’s fortunes.

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