Dominic Cummings, former Chief Strategy Adviser to the British Prime Minister, was seen carrying his belongings in a cardboard box as he left 10 Downing Street on Friday, following his resignation.
Replacing him, The Daily Telegraph reports, could be former chancellor Sajid Javed, who would take over as chief of staff.
In January early this year, Cummings had blogged about the need for reforms within the civil service, noting it lacked people with “deep expertise in specific fields”. In it, he said he wanted ot make himself “largely redundant” within a year.
Cummings made headlines in March for breaking lockdown rules by driving 260 miles form his home to Durham, ignoring guidelines to stay at home despite not serving his quarantine period following being symptomatic.
There were resounding calls for him to step down or be sacked but he instead hosted a press conference to deny allegations of wrongdoing.
"He'll be missed... But advisers come and go," UK Transport Secretary Grant Shapps told Sky News.
“In any government, you require people who are going to shake things up and come up with ideas, and he's actually been that person," he said.
However, according to sources being quoted across the UK media, the exit of one of his own close allies in Downing Street—Lee Cain as the No. 10 Director of Communications—had precipitated his exit plans.
Commings and Cain both worked with Johnson as part of the Vote Leave campaign during the 2016 European Union (EU) referendum and are seen as instrumental to the Brexit outcome.
They are widely regarded to have since led a Vote Leave faction of colleagues in Number 10 and other parts of government.
Cain, 29, had announced he would step down as Johnson's top media aide on Wednesday night after ministers and advisers, including Johnson’s fiancee Carrie Symonds, are said to have protested over his planned promotion to Chief of Staff. Symonds, a former head of communications for the ruling Conservative Party, is believed to be unhappy with the influence of some of her husband-to-be's closest aides.
The high-profile departures from Johnson’s top team follow the appointment of former BBC journalist Allegra Stratton as Downing Street's new TV spokesperson who will be hosting White House style briefings from the New Year. Symonds is said to be close to and more aligned with Stratton’s way of working.
Johnson is looking to fill the post of Chief of Staff as part of a wider reorganisation at the very top of his government structure
However, several members of Parliament from within the Conservative Party have expressed dismay at the internal wrangling of No. 10 spilling out into the public domain.
It comes at a time of growing unease on the Tory benches at the government's handling of the pandemic and the economic damage being caused by the current lockdown in England.
But Johnson’s official spokesperson, James Slack, who will replace Cain when he departs in the New Year, tried to diminish the reports of any bitter power struggles behind closed doors.
"You've seen from the Prime Minister this week that he's absolutely focused on taking all the steps that are required to equip the country to beat coronavirus," he said.
With inputs from agencies
