Video report by ITV News Political Correspondent Daniel Hewitt
Westminster is in a tizzy after the resignation of Boris Jonson's chief spin doctor, Lee Cain, throwing Number 10 into turmoil.
An ugly, bitter power struggle at the heart of Downing Street has now spilled out into the public eye - but why does it matter and what does it all mean?
What has happened?
Lee Cain is quitting the Number 10 operation.
He had been the Prime Minister's director of communications and will remain in post until the end of the year, but he was effectively forced out by warring factions in Downing Street.
Mr Cain had been offered a promotion to become the PM's chief of staff, but a leak of that news prompted backlash within Tory ranks.
Most notably Mr Johnson’s fiancee Carrie Symonds was one such critic, as well as new media mastermind Allegra Stratton.
Why should I care?
Rifts, rows and speculation about who is in and who is on the way out are a part of everyday life in Westminster.
What's different this time is the turmoil is playing out during a time of national crisis.
The country is in the midst of the Covid-19 second wave, with the official death toll passing 50,000 and the true figure much higher.
Given all of that, the public might have expected those involved in running the country to have been more focused on the pandemic rather than internal squabbling. Alas, no.
Why is Lee Cain controversial?
Mr Cain, a former tabloid journalist, was one of the key players in the Vote Leave campaign for Brexit.
He worked alongside Dominic Cummings and was rewarded with a role in Boris Johnson's government.
Before that Mr Cain made a name for himself while working for the Daily Mirror, he was the man who dressed up as a chicken to torment then Conservative leader David Cameron.
His background in journalism proved handy for Downing Street, Mr Cain fought a divisive battle with the press which culminated in a walkout by senior members of the reporters covering Westminster.
It came after journalists from some outlets were banned from a briefing on UK-EU trade talks.
So why has he fallen out of favour?
Mr Cain is said to have been aggrieved at former broadcast journalist's Allegra Stratton's appointment as the face of Downing Street's televised briefings.
Fearing being sidelined, Mr Cain is reported to have offered his resignation as communications chief but says he was offered the powerful role of chief of staff.
That move prompted anger and concerns it would entrench the group of the Brexit campaign on No 10.
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”.
What impact has his resignation head?Top dog Dominic Cummings was reportedly considering his position after Mr Cain quit, but as of Thursday morning it appears he will remain in Number 10.
The position of Lord Frost, the Prime Minister’s Europe adviser, was also reported to be uncertain, although he too appears to be staying.
But just the fact there was speculation about Lord Frost's role - at a time when post-Brexit trade talks are at crisis point - is another alarming sign that all is not well in Downing Street.
What next in the saga?
It comes back to the appointment of Ms Stratton as the new face of Downing Street's press conferences.
She is thought to have wanted direct access to the PM - rather than reporting to Mr Cain in order to do her job more effectively.
There is no fixed date yet for the start of those briefings, but Mr Johnson hopes they will help improve the government’s public image.
The post-Brexit trade talks are entering their end game, with a resolution needed shortly if a deal is to be implemented in time.
So the weakened position of the Vote Leave contingent within Number 10 could make it easier for Mr Johnson to compromise - despite his repeated insistence he is prepared to walk away without a deal.