Amber Rudd challenges Boris Johnson to reject 'dark arts' of campaigning in Tory leadership race

Rumours rife in Westminster about the frontrunner "lending" votes in the hope of knocking out Gove

Cabinet minister Amber Rudd has issued a challenge to Boris Johnson to reject the “dark arts” of election campaigning during the battle for the Conservative leadership.

With the contest to replace Theresa May down to the final four candidates, rumours are swirling around Westminster of the frontrunner “lending” supporters to other contenders in order to ensure he faces Jeremy Hunt in the final run-off.

The dramatic collapse in outsider Rory Stewart’s support on Wednesday prompted speculation that Johnson-backing MPs had given him their votes the previous day to knock out Dominic Raab, the only candidate who could take on the favourite from a hard Brexit position.

Now there are claims that Mr Johnson’s campaign lieutenant Gavin Williamson is pushing sympathetic MPs to derail Michael Gove’s bid by lending their support to home secretary Sajid Javid.

The Johnson camp dismiss any suggestion of vote-lending as “nonsense” and sources close to Mr Javid insist that they have seen no evidence of him benefiting from the tactic.

But Ms Rudd said it was time for the former foreign secretary to publicly disavow any underhand tactics.

The work and pensions secretary told BBC Radio 4's Today programme: "I find all this conversation about lending votes rather discrediting of the system.

"I would really call on Boris himself to repudiate the information that is coming out of 'friends of Boris', saying this, saying one thing."

Ms Rudd, who backs Mr Hunt in the race for Downing Street, added: "This is a serious moment. We don't need that sort of game-playing going on in Parliament."

(AFP/Getty Images (AFP/Getty Images)

With a commanding tally of 143 in the third round of MPs’ votes on Wednesday and a lead of 89 over second-placed Mr Hunt, there is no doubt that Mr Johnson has ample scope to redirect some of his supporters to another candidate to secure his favoured opponent for the postal ballot of 160,000 Conservative members who will decide on the new leader.

Many at Westminster believe he would prefer to face the formerly Remain-backing foreign secretary than the man who led the Vote Leave referendum campaign with him and then sabotaged his bid for the Tory leadership in 2016.

There was no immediate response to Ms Rudd’s challenge from the campaigns of either Mr Johnson or Mr Gove.

And “team Saj” brushed off suggestions that he was benefiting from borrowed support, insisting that they had identified between 37 and 39 MPs who they expected to vote for him ahead of Wednesday’s ballot, when he eventually secured 38.

“What Gavin does is Gavin’s own look-out,” said one source. “But some of this falls into the box of ‘Too clever by half’. We have no evidence that any of these tactics exist.”

Ahead of the final two rounds of voting on Thursday rival candidates were jockeying for the support of the 27 MPs who backed the eliminated Mr Stewart.

The bulk are expected to switch to Mr Hunt, as the remaining contender most wary of a no-deal Brexit, or to Mr Javid, who has also presented himself as a “change” candidate capable of reaching out beyond the Tory base.

The international development secretary himself has said he will vote, but has declined to endorse any candidate publicly.