The second round of voting among Conservative MPs takes place today to determine which two candidates will be decided on by the party's membership to replace David Cameron as prime minister.

On Tuesday, Theresa May surged into the lead, gaining the support of half of all Conservative MPs in the first round of voting. May, the Home Secretary, won 165 votes while Energy Minister Andrea Leadsom gained 66, Justice Secretary Michael Gove came third with 48, Work and Pensions Secretary Stephen Crabb won 34 votes and Liam Fox achieved 16.

Crabb voluntarily pulled out of the race after Fox was eliminated. Both men said they were backing May.

The question today is whether Leadsom or Gove go through to the next stage of the conterst, in which 130,000 members across the country will decide between the top two.

Westminster is rife with speculation about a 'plot' to rig the vote in favour of Gove, after his ally and fellow MP Nick Boles was revealed to be sending messages to MPs supporting May urging them to 'lend' their vote to Gove on the grounds that Leadsom is a "dangerous" candidate.

Boles said that Gove would not mind "spending two months taking a good thrashing from Theresa ... if it that's what it takes to stop AL [Andrea Leadsom]."

A 'confidential' message from Boles to at least one MP, which ended with a kiss, said: "I am seriously frightened about the risk of allowing Andrea Leadsom on to the membership ballot. What if Theresa stumbles? Are we really confident that the membership won't vote for a fresh face who shares their attitude about much of modern life? Like they did with IDS [Iain Duncan Smith, the Conservative leader from 2001 to 2003]."

Last night during a party hustings, Gove was challenged about the message by a Tory MP, Graham Stuart, a Conservative MP and according to an MP present Gove "giggled" and did not deny that Boles had been sending such messages.

Boles has apologised for the messages and claimed that Gove did not know of them.

Meanwhile, the Sun and the Mail, both supportive of Gove, have been running negative stories about Leadsom.

Some moderate MPs fear that if right-winger Gove got through to the final stage, he could beat May in the membership stage of voting, with the front-runner eventually losing, as has been the case in a number of relatively recent Tory contests.