Boris Johnson is being lined up to mount a Tory leadership bid to save the party and Brexit

BORIS Johnson is being lined up to mount a Tory leadership bid.

Plotters fear Theresa May will not survive the summer and are urging the Foreign Secretary to save the party and Brexit.

They are convinced their lame duck PM could be toppled at any time and want a “clean and swift” succession.

Mrs May’s position was further weakened yesterday when her two most trusted aides were forced to quit.

Nick Timothy and Fiona Hill, the PM’s joint Chiefs of Staff, resigned after ministers threatened a leadership contest unless they went.

They were accused of creating a “toxic” atmosphere at No 10. Staff said the pair bawled at ministers and fired off rude texts to anyone who failed to toe the line.

Tory generals yesterday admitted Mrs May was a caretaker at No 10 until they agreed on a replacement.

Boris is their favourite but has yet to be told he is the popular choice.

It would be an astonishing comeback almost a year after he pulled out of his last leadership bid — giving Mrs May a clear run for the crown.

At least three MPs have been asked to be stalking horse candidates to trigger a contest.

One who refused said: “They’ve told me there’s no way I will become leader, but will pave the way for a big gun to enter the race. My rewards will come later, I’m told. I’m not getting involved.”

Mrs May will get time to start the Brexit process before the “men in grey suits” say her time is up.

They will act sooner if she suffers a Commons loss that could force a second election – which she would be odds-on to lose.

Former aide Joey Jones, who worked for Mrs May at the Home Office, said she was being humiliated by her party.