An ugly and bitter power struggle at the heart of Downing Street has spilled over into the public eye during a crucial stage of the coronavirus pandemic.

It has so far led to the resignation of director of communications Lee Cain but it is unlikely the turmoil will now be abated.

Here is a look at some of the key players in the dispute:

Allegra Stratton

A former broadcast journalist, Ms Stratton first crossed the divide in April when she entered the Treasury as Chancellor Rishi Sunak’s communications chief.

But she was swiftly poached by the Prime Minister to be the face of Downing Street in planned US-style televised press briefings. Her hiring was reportedly a move Mr Cain opposed and he took it as a blow to his authority. Long-simmering tensions in No 10 began boiling over.

Lee Cain

A long-term ally of Mr Johnson, he worked in Vote Leave’s communications team and joined Mr Johnson in government during his time as foreign secretary. The spin doctor stuck by his boss when he quit over Theresa May’s Brexit deal and worked on his successful campaign to succeed her as Tory leader, and Prime Minister.

Mr Cain started his career in local news before entering the world of tabloid journalism, where he memorably dressed up as a chicken to torment then Conservative leader David Cameron while at the Daily Mirror.

Aggrieved over Ms Stratton’s appointment and fearing being sidelined, he is said to have offered his resignation as communications chief.

But he says he was offered the powerful role of chief of staff, which would have put him in charge of the day-to-day operations at Downing Street and made him one of just a handful of people with direct one-to-one access with the Prime Minister. The shake-up prompted anger and concerns it would entrench the group of the Brexit campaign on No 10.

That his supposed appointment was leaked early, much like the lockdown announcement now subject to a leak inquiry, ratcheted up tensions and aroused suspicions.

Disliked by many on the Tory backbenches for his pugnacious style and much-criticised communications strategy during the pandemic, he said on Wednesday that he would leave his role by the end of the year. He said he had decided to resign after “careful consideration”, while Mr Johnson thanked him for his “extraordinary service”.

Carrie Symonds

The Prime Minister’s fiancee is an ally of Ms Stratton and a former communications director for the Conservative Party.

She has clashed with Mr Cain in the past, and apparently raised objections to his appointment as chief of staff.

Dominic Cummings

The former Vote Leave director who is Mr Johnson’s chief adviser. A highly-controversial figure for a host of reasons, he is a close ally of Mr Cain’s, having worked together in the Brexit campaign.

Some suggest he had threatened to resign over his friend’s treatment, but he has not yet done so.

He did not stand down over the Barnard Castle affair that is said to have undermined trust in the Government during the first lockdown, so it remains to be seen what he would budge for and whether any suggestions of his departure are for show.

Many in Government would not be sorry to see him ousted. He is an abrasive figure and his open contempt for MPs and other advisers has unsurprisingly won him many enemies in Whitehall.

James Slack

A former Daily Mail journalist who serves as the Prime Minister’s official spokesman, a role he also held under Mrs May. A member of the permanent Civil Service, he is expected to succeed Mr Cain as director of communications.