Penny Mordaunt has rejected an appeal from Boris Johnson to drop out of the Conservative leadership contest and back his bid, sources close to the Commons leader have said.
With just 25 public declarations of support from MPs, Ms Mordaunt is seen as the candidate least likely to top the 100 threshold required to secure a place on the ballot paper on Tuesday.
But it is understood that she insisted she will remain in the race to replace Liz Truss as Tory leader and prime minister.
And she told Mr Johnson that the bulk of her supporters would switch to his main rival Rishi Sunak if she dropped out.
Candidates have until 2pm on Monday to provide 100 nominations, with an online ballot of party members triggered if two of them overcome this hurdle.
Only Mr Sunak has so far amassed the necessary numbers, with 151 public declarations of support to Mr Johnson’s 63, though the former PM’s supporters insist that private backers bring his total past the 100 threshold.
By Sunday afternoon, the former chancellor was closing in on the crucial tally of 179, which represents more than half of the Conservative parliamentary party and would make it impossible for him to be overhauled.
There was no immediate response from the Johnson camp to reports of his talks with Ms Mordaunt.
