Boris Johnson 's allies fear that he faces yet more damaging stories about his personal integrity that could derail his plans to move on to other issues.
Tory rebels are keeping up pressure on the Prime Minister's probity after he narrowly won a vote of no confidence in his leadership last night.
Mr Johnson's reputation has been battered in recent months by the Partygate scandal, his lavish refurb of the Downing Street flat and his attempts to water down the ministerial code.
Tory sources say they are worried there could be more to emerge which could undermine his efforts to shore up support.
One former Cabinet minister suggested there was a "pipeline of f***-ups" likely to emerge in the coming months which would dent Conservative poll ratings still further.
A second ex-minister minister said: "Watch for the next crisis. There's bound to be another one round the corner."
Labour's deputy leader Angela Rayner accused the PM, who is under investigation by MPs over lying to Parliament on Partygate, of "downgrading" British values.
She added: "This Prime Minister's example of leadership: illegally proroguing parliament, breeding a Downing Street culture where his staff felt able to break lockdown rules including himself, putting the very standards that underpin our democracy to the shredder."
Mr Johnson was challenged by Tory MPs over his integrity at a meeting ahead of the confidence vote.
Party insiders claimed that the PM had "pulled a face" when asked why he had removed references to "honesty and integrity" from the ministerial code.