The race for the Tory leadership took a bitter new twist as Justice Secretary Michael Gove was confronted at election hustings about a text apparently from his campaign team to supporters of Theresa May which appears to urge them to vote tactically to block Andrea Leadsom from reaching the final two.

The text, which pro-May supporters claim has been sent to scores of MPs, warns that if energy minister Ms Leadsom makes the run-off after Thursday's final crunch vote, party members could propel her to the leadership in the same way they did Iain Duncan Smith.

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One pro-May MP said after the hustings that the text, which he said was sent by one of Mr Gove's campaign team, stated: "I would be really grateful if you would treat this in strict confidence.

"You are my friend, I respect the fact that you want Theresa May to be the Prime Minister. It is overwhelmingly likely that she will be, and if she does I will sleep easily at night.

"But I am seriously frightened about the risk of allowing Andrea Leadsom onto the membership ballot.

"What if Theresa stumbles? Are we really confident that the membership won't vote for a fresh face who shares their attitudes about much of modern life, like they did with IDS?

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"I am not asking you to respond unless you positively want to have a chat, but I hope that you will reflect on this carefully.

"Michael doesn't mind spending two months taking a good thrashing from Theresa if that is what it takes to put the party's interest and the national interest, surely we must all work together to stop AL?"

The MP said the text was signed by an X, representing a kiss.

READ MORE: Conservative MPs urge party to speed up leadership contest

Mr Gove was challenged about the text at the hustings, MPs present said, with a May supporter stating the Justice Secretary responded to the challenge with "a sort of giggle, and then he sat down. He didn't disown it, because so many MPs have received it, it is quite difficult to disown it".

However, an MP who is supporting Mr Gove said he handled the situation well and the mention of the text was not a key moment of the meeting.

Mr Gove was also challenged for the first time at hustings about what some MPs see as his "betrayal" of Boris Johnson, but the Justice Secretary said he had decided to run himself because he thought the ex-London mayor was not suited for the job.

The hustings also saw Ms Leadsom say that she would not be releasing her tax returns, as other candidates have, unless she made the run-off.

The minister told MPs that they could come to see a summary of her tax affairs personally if they wanted to.

Supporters said that Ms Leadsom did not want to set a "precedent" where bidders for high office would have to make their financial affairs public as a matter of routine.

In a reference to her comments about babies' frontal lobes at Monday's hustings, Ms Leadsom told the gathering: "I'm a quick learner, no more talk about babies' brains."

Referring to unguarded comments recorded by Sky News by Tory former chancellor Ken Clarke in which he referred to Mrs May as "a bloody difficult woman", the Home Secretary joked that the next person to take that view of her would be Jean-Claude Juncker, the European Commission president.

Former leader Mr Duncan Smith moved to brush off the anti-Leadsom message sent to supporters of Mrs May, saying: "People with knives will end up stabbing themselves. Whoever wins this contest has to bring the party and country back together. I do think emails or texts like that are failing to smell the coffee, wake up and recognise we want to come back together, and govern as a Conservative Party, that we can get on with each other and do not want to spend the whole time stabbing each other in the back."

The hustings came as 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 Mrs 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 Ms Leadsom.

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 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.