Conservative MPs who support all three remaining leadership candidates are urging the party to speed up the contest so a new prime minister is chosen by the end of the month.

A growing group of around 30 MPs have signed a letter written by former Tory chairman Grant Shapps, which calls on the party to give members three weeks to pick a leader after the third place candidate is eliminated on Thursday.

Mr Shapps, who supports frontrunner Theresa May, denied it was a "wheeze" to secure her the leadership on the basis that she is more well known among members than likely rival and junior minister Andrea Leadsom.

He said he had the support of MPs who back both women, as well as Michael Gove, who finished in third place in the first round of voting.

Mr Shapps told the Press Association: "This is not some clever plot or wheeze but we have a responsibility to our constituents to give some direction to the party and get a prime minister in place."

The former minister will send his letter to party chairman Lord Feldman after gathering the support of more MPs.

In it he wrote: "Given the exceptional post-Brexit times in which we are living, I firmly believe that it is now wrong to wait for a final decision to emerge next autumn.

"Ongoing instability on the markets now risks uncertainty with investment decisions being delayed. This in turn will have real-life consequences for jobs, livelihoods and the security of families across Britain."

Mr Shapps said the process of whittling down the candidates has been far quicker than many thought, with the final two to be known on Thursday, rather than at the beginning of summer recess as expected.

With the accelerated timetable, the final two candidates would have a three-week period to make their case at hustings, during which time members can cast their ballots, following the rules for British overseas voters in general elections.

Mr Shapps added: "We are living through unprecedented times and, unusually, this leadership election is occurring whilst we are in office; meaning that we are electing a prime minister.

"The country desperately needs post-Brexit direction in order to avoid a political vacuum bearing serious consequences for all those we represent."

Mrs May has insisted she does not want a "coronation" as Conservative leader, after emerging as overwhelming frontrunner in the race to succeed David Cameron.

The Home Secretary is in pole position for the Tory leadership after getting the votes of half the party's MPs (165) in the first round of the contest on Tuesday, and securing the backing of two rivals.

She is expected to be confirmed on Thursday as one of the two contenders chosen by MPs to go forward in a vote of around 150,000 Conservative members to elect a new leader - and prime minister - on September 9.

In a statement ahead of an MPs' hustings on Wednesday, Mrs May said that Tuesday's vote showed she was the only candidate able to "unite our party and the country, to negotiate the best possible deal as we leave the EU, and to make Britain work for everyone".

She insisted: "I have been clear from the start: the party and the country deserve an open, honest, robust debate - and the next leader needs to have won a mandate to lead.

'So there should be no deals, no tactical voting, and no coronation."

Mrs May's supporters have dismissed suggestions that some of her backers tactically "lent" their support to Mr Gove on Tuesday in the hope of keeping energy minister Mrs Leadsom off the ballot paper.

Although the Home Secretary enjoys an unassailable lead among MPs, some supporters fear that her path to the leadership could still be blocked by Eurosceptic activists' preference for a Brexit campaigner like Mrs Leadsom.