AMBER RUDD is set to pile in behind her rival Boris Johnson if he makes a leadership bid, it was reported today.

The Home Secretary apparently wants a promotion to Chancellor if Theresa May ends up quitting - instead of making a run for the top job herself.

2 Amber Rudd is reportedly set to back Boris Johnson for the Tory leadership Credit: Getty Images - Getty

It is claimed that Ms Rudd would support Boris if he went for the leadership, despite fierce clashes between the pair in the past.

The two senior figures are both supportive of Mrs May but are ready to pounce if the PM quits in the next couple of years, the Mail on Sunday reported.

In a leadership election, Mr Rudd and Mr Johnson would be among the top favourites to take over.

But their supporters apparently believe that combined they would be unstoppable - with Ms Rudd's reputation for straightforward competence balancing out Boris' bravado.

2 The Foreign Secretary is favourite to be the next Tory PM after Theresa May Credit: Reuters

An ally of the Home Secretary told the newspaper: "They would be unbeatable. A balanced ticket of Brexit and Remain, and she would act as a brake on his wilder excesses."

If the pair did team up, it would be a remarkable turnaround given the clashes between them in the past.

During the Brexit referendum campaign, Ms Rudd mocked Boris saying: "He’s the life and soul of the party.

"But he’s not the man you want to drive you home at the end of the evening."

And last month, when the Foreign Secretary was accused of undermining Mrs May on Brexit, Ms Rudd took aim at him again.

She said he was "backseat driving" and commented: "I don’t want him managing the Brexit process."

The Home Secretary has a tiny majority in her home constituency which is believed to make her reluctant to stand for the leadership of the Tories.