Boris Johnson still has control of Downing Street after a string of close aides quit their jobs, his official spokesman has insisted.
Mr Johnson quoted The Lion King as he attempted to rally remaining staff, telling them “change is good”.
His spokesman said No 10 was “not currently” expecting more resignations in the coming hours.
But a former minister has become the latest Conservative MP to submit a letter of no confidence in Mr Johnson.
Nick Gibb said his constituents were “furious about the double standards” and said Mr Johnson had been “inaccurate” during statements in the Commons.
Many have cited the PM’s participation in parties with staff in No 10 during lockdowns as their motivation to challenge Mr Johnson.
Earlier, MP Aaron Bell – who criticised Mr Johnson over lockdown parties in the Commons earlier this week – said the “breach of trust” over the rule breaking and how it had been handled made the PM’s position “untenable”.
The Metropolitan Police has launched an investigation into 12 of the parties and a full report by Ms Gray is expected to be published afterwards.
And the wave of departures from Mr Johnson’s top team adds to the feeling of instability around him.
Mr Johnson’s official spokesman told reporters that three of Thursday night’s departures – Jack Doyle, Dan Rosenfield and Martin Reynolds – had come as a result of “mutual decisions”.
But the exit of head of policy Munira Mirza and policy advisor Elena Narozanski had not been planned.
Backbencher Tory MP Huw Merriman told BBC Radio 4’s Today programme the PM should “shape up or ship out”.
But Levelling Up Secretary Michael Gove said it was “the best thing for the country” to keep Mr Johnson in post.