Britain's health minister Matt Hancock quit on Saturday after he was caught breaking Covid-19 rules by kissing and embracing an aide in his office, enraging colleagues and the public who have been living under lockdown.

The 42-year-old wrote to British Prime Minister Boris Johnson to resign after The Sun newspaper published photos of the married minister embracing a woman who he had appointed to a taxpayer-funded role to scrutinise the performance of his department.

Hancock has been at the centre of the government's fight against the pandemic, routinely appearing on the television and radio to tell people to follow the strict rules to contain the virus.

“We owe it to people who have sacrificed so much in this pandemic to be honest when we have let them down as I have done by breaching the guidance,” he said in the letter.

Johnson said in reply that he was sorry to receive it.

“You should be immensely proud of your service,” he wrote. “I am grateful for your support and believe that your contribution to public service is far from over.”

The Sun showed Hancock kissing the aide in his office last month, at a time when it was against the rules for people to have intimate contact with a person outside their household.

Hancock had issued an apology on Friday. “I accept that I breached the social distancing guidance in these circumstances,” Hancock said. “I have let people down and am very sorry.”

But Britain's leading newspapers, which all splashed the story on their front pages, said Hancock had lost any moral authority and must go.

“Hancock cannot now hope to put on a straight face and tell us how to behave and seriously expect us to listen,” The Sun said in its leader column. “There is the rank stench of hypocrisy.”

The opposition Labour Party had also questioned whether he had broken the ministerial code; the woman, a long time friend of Hancock's, was appointed as a non-executive director, on a taxpayer-funded salary, to oversee and scrutinise the running of his department.