Health Secretary Matt Hancock is facing mounting pressure to resign after he was filmed kissing an aide in breach of COVID-19 regulations.
A video of Mr Hancock, who is married, embracing Gina Coladangelo has been published in The Sun after stills from the CCTV clip were released on Friday, prompting the health secretary to issue a statement saying he had "let people down" and was "very sorry".
Lawyers are debating whether Mr Hancock has broken his own law regarding coronavirus restrictions, although he has admitted only to breaching guidance.
The Metropolitan Police has said it is not investigating any offences, which allegedly took place last month, because "as a matter of course the MPS is not investigating COVID-related issues retrospectively".
There are also questions about Ms Coladangelo's appointment to her role in the Department of Health and Social Care (DHSC) in the first place.
Downing Street said Boris Johnson accepts Mr Hancock's apology and "considers the matter closed", but a Labour spokeswoman accused the prime minister of being "spineless", adding: "This matter is definitely not closed, despite the government's attempts to cover it up."
A snap poll from Savanta ComRes, released hours after photographs of the pair kissing in Mr Hancock's ministerial office surfaced, found 58% of UK adults thought that the health secretary should resign, compared to 25% who thought he should not.
Campaign group COVID-19 Bereaved Families for Justice said the PM's backing for Mr Hancock was a "slap in the face" for families who had lost loved ones to the virus.
"Up and down the country, bereaved families have been doing everything they can to follow the rules and prevent further loss of life," the group said.
"But it's clear Matt Hancock thought that 'hands, face, space' was a rule for everyone else."
Labour Party chair Anneliese Dodds said: "He set the rules. He admits he broke them. He has to go. If he won't resign, the PM should sack him."
Liberal Democrat MP Layla Moran, who chairs the all party parliamentary group on coronavirus, accused Mr Hancock of "utter hypocrisy" and questioned Mr Johnson's response - saying whether or not he accepted the apology was "irrelevant".
And it's not only Labour and the Liberal Democrats who have called on the PM to sack the health secretary.
There are reports that some Tory MPs have also told the prime minister to "pull the plug", with public reaction over coming days key to Mr Hancock's fate.
But former Conservative minister Edwina Currie - who had an affair in the 1980s with former prime minister John Major, defended Mr Hancock's refusal to resign saying "private lives are private".
Ms Currie told Times Radio: "I think also we should be very wary of being terribly censorious and pious that we want perfect behaviour from ministers."
According to The Sun newspaper, the CCTV footage was taken on 6 May from the DHSC building.
At the time the picture was reportedly taken, guidance said people should keep their distance from anyone not in their household or support bubble.
Legislation in force at that point also said "no person may participate in a gathering" that "consists of two or more people... and takes place indoors".
There was an exception for "work purposes or for the provision of voluntary or charitable services", but it is not clear whether the health secretary believes the embrace was part of a work meeting.
Adam Wagner, a human rights barrister from Doughty Street chambers who has analysed COVID restrictions closely over the course of the pandemic, told Sky News it is "quite likely" the health secretary broke the law.
"Unlike any other country in Europe we were banning relationships effectively, banning people meeting up indoors," he said.
"So I'm absolutely certain if you'd asked Matt Hancock about this exact question, if somebody was at work and decided to have an affair with a co-worker, went and met in different places to have that affair, would that be within the law, he would have said no."
The Sunday Times reported in November that Mr Hancock had failed to declare he had appointed Ms Coladangelo as an unpaid adviser on a six-month contract last March and later gave her a role on the board of the DHSC.
Ms Coladangelo, who is listed on the department's website as a non-executive director, is the marketing and communications director at British retailer Oliver Bonas, which was founded by her husband Oliver Tress.
Her LinkedIn profile says she has been working as a non-executive director at the department since September 2020 and was at Oxford University at the same time as the health secretary.
Mr Hancock has been married to his wife Martha for 15 years and they have three children together.