Boris Johnson's Conservative government is in deep crisis, engulfed once more in a scandal that is at least in part of the Prime Minister's own making.

And this time, it's a lot worse than all the other times.

On Tuesday evening, after days in which Downing Street has been on the ropes over its handling of allegations of sexual misconduct by a member of the government, two senior Cabinet ministers quit.

Health Secretary Sajid Javid said he could not "in good conscience" continue. Finance minister Rishi Sunak also resigned, saying that people "rightly expect government to be conducted properly, competently and seriously."

The immediate cause of the crisis was the fallout from the resignation last Thursday of deputy chief whip Chris Pincher, amid allegations he had groped two guests at a private dinner the night before. While he did not admit the allegations directly, Pincher said in a letter to Johnson that "last night I drank far too much" and "embarrassed myself and other people."

What landed Johnson in deeper trouble, though, were the contortions that Downing Street press officers went into trying to explain why Pincher was ever in government in the first place, amid a wave of revelations of his previous conduct. On Tuesday, a senior former civil servant published a letter effectively accusing Downing Street of not telling the truth when it said the Prime Minister was not aware of at least one of the historical allegations.