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 another MP has submitted a letter of no confidence in the PM as the leader battles to save his own job.
Posting on Twitter, 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”.
Backbench unrest is growing within the Conservative Party, with the BBC aware of 17 Tory MPs who have submitted no confidence letters in the prime minister – 54 are needed to trigger a leadership contest.
Many have cited the PM’s participation in parties with staff in No 10 during lockdowns as their motivation to challenge Mr Johnson.
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”.
The minister – who once claimed Mr Johnson was not up to the job of prime minister – denied the government was in disarray, saying: “The PM wanted change and he said there would be change, and we’re seeing that change now.”
The PM held a meeting with staff on Friday, acknowledging it was a “challenging time” in No 10, but he tried to reassure colleagues by quoting Rafiki from Disney’s The Lion King, saying “change is good”.
His spokesman said Mr Johnson also “reflected on the privilege of working in No 10” and “thanked those who are leaving for their contribution alongside the whole team for their work”.
But Labour’s shadow employment minister, Alison McGovern, said the situation in Downing Street looked like “an absolute pantomime”, adding: “Boris Johnson, the one who should be resigning, will be the last one out of the door.”It doesn’t exactly exude confidence the fact that so many people are walking out.”
