Health Minister Sajid Javid says he can't continue 'in good conscience', while Chancellor Rishi Sunak says the public 'rightly expects' government to be conducted 'properly.'
Their letters of resignation came as Boris Johnson was apologising for promoting an MP, with a history of complaints against him.
Alaistair Campbell was Tony Blair's spokesperson at Downing Street - he believes this is the end of Boris Johnson's premiership:
"He should have resigned about 15 times already. Boris Johnson should never ever ever have been Prime Minister. All he'll be thinking of at this minute is 'can I survive?' That is the only question that he cares about, and meanwhile the country's getting damaged so I think he's toast- I'm glad that he's toast."
Sky's political editor Beth Rigby says both new departures are a massive blow for the Prime Minister Boris Johnson:
"He's lost his chancellor and he's lost his Health Secretary and he has lost his party chair. Now there are questions about whether the Prime Minister could be forced out by cabinet no longer willing to support him. Could this now be the beginning of the end?"
