Number Ten Policy Unit member Elena Narozanski has announced that she will leave Downing Street amid the ongoing scandal around the "partygate" allegations, according to Conservative Home.
The Number 10 Policy Unit is an elite body of lawmakers who provide policy advice directly to the prime minister.
Narozanski, according to The Telegraph, was an important part of Johnson’s policy team, particularly leading on sport policy within the Number 10 Policy Unit.
She is the latest one to part ways with Boris Johnson's office, with her decision reported shortly after four senior PM aides announced they will not be working in Downing Street anymore.
Among those who decided to resign were the prime minister's director of policy Munira Mirza, director of communications Jack Doyle, the prime minister's chief of staff Dan Rosenfield, and Johnson's principal private secretary Martin Reynolds.
According to The Telegraph, Andrew Griffith, who is to replace Mirza as policy chief, has braced for more resignations to come.
The apparent exodus comes in the wake of the "partygate" fallout, with Downing Street accused of "serious failures of leadership and judgement" by senior civil servant Sue Gray, who has investigated a slew of allegations about parties being held at No 10 during the times of the strict coronavirus lockdown.
After Mirza's surprise departure, Boris Johnson announced that there would be a shake-up among the MPs in light of the "partygate" report. A Whitehall insider, cited by The Telegraph, said that her resignation encouraged No 10 to bring forward plans for the overhaul, which were scheduled to be announced next week.
Greg Hands, the UK's energy minister, told Sky News before the news of Narozanski's departure that the wave of resignations were evidence of the prime minister "taking charge".
Johnson, however, faces calls to resign himself, with Downing Street trying to steer clear of commenting on the "partygate" allegations before the police investigation into the claims is finished. Still, the prime minister pledged to "comply with the law" if he was found guilty of breaching coronavirus rules by the police.
As the "partygate" rattles Downing Street, several Tory MPs have filed their letters of no confidence in Johnson, with UK media speculating that over a dozen lawmakers have joined the effort to oust the prime minister. However, in order for a vote on it to be triggered, at least 54 such letters are needed.