New Tory leader to be announced on July 23 but party fails to reveal when he will become prime minister

The new Conservative leader will be announced on Tuesday 23 July, the party says – but the date when he will become prime minister is still being kept under wraps.

Voting in the leadership contest will end at 5pm on the day before, with the winner unveiled after overnight counting.

However, a brief statement failed to shed light on whether Theresa May would remain in No 10 for a swansong prime minister’s question time the following day, before resigning.

Some MPs have protested such an arrangement could allow her successor to escape scrutiny until the autumn – because their long summer recess begins one day later, on Thursday 25 July.

Aides to Boris Johnson and Jeremy Hunt were told the winner of the leadership race will not move into No 10 immediately on 23 July, as widely expected.

There is a precedent from 2007, when Gordon Brown was declared the new Labour leader three days before becoming prime minister, so Tony Blair could enjoy a valedictory last Commons appearance.

The issue was raised in the Commons on Monday evening, when Sarah Wollaston, an Independent MP, described it as “an extremely grave matter”, given the Brexit crisis.

She urged John Bercow to “make sure that the next prime minister can be held to account by this House without there being an extended period of summer recess in the way”.

Mel Stride, the Commons Leader, then tried to reassure MPs that it was “not the government’s intention” for the new prime minister to escape appearing before MPs until the autumn.

He suggested MPs would force an appearance if necessary, adding: “Parliament would express its will if there were any likelihood of that becoming an issue.”

Labour has vowed to table a vote of no confidence, which could be staged on that Thursday, but, otherwise, there would no reason for the new prime minister to appear before MPs.

However, it could put off the vote until the autumn, when it has more chance of succeeding when the UK could be closer to a no-deal Brexit.

In the statement, the Conservative party confirmed 15 more leadership hustings over the next four weeks, after the focus on Mr Johnson’s altercation with his partner at the first, last Saturday.

There will also be a “digital hustings” to be live-streamed on the Conservative Party’s Facebook and Twitter accounts.

The statement said: “Conservative Party members should receive postal ballots between 6 and 8 July. This ballot will close at 5 pm. on Monday 22 July.”

And it added: “The announcement of the next leader of the Conservative Party will be made on Tuesday 23 July. This process has been agreed with both candidates.”