Photographs were published by The Sun newspaper appearing to show the health secretary kissing Gina Coladangelo in his Whitehall office last month.
The newspaper published a series of photos – and later a video – that appeared to show the senior politician embracing and kissing his aide.
The revelation prompted widespread outrage at the breach of social distancing rules and questions about Ms Coladangelo’s appointment to a £15,000-a-year role within the Department of Health.
Now Mr Hancock – who was made Secretary of State for Health and Social Care in July 2018 – has handed in his resignation
In his resignation letter addressed to the prime minister, the 42-year-old politician wrote: ‘The last thing I would want is for my private life to distraction attention from the single-minded focus that is leading us out of this crisis. I want to reiterate my apology for breaking the guidance, and apologise to my family and loved ones for putting them through this. I also need to be with my children at this time.
‘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.’
In a letter of reply, the prime minister Boris Johnson said the former health secretary should leave office ‘very proud’ of what he had achieved.
He added: ‘Above all, it has been your task to deal with a challenge greater than that faced by an of your predecessors, and in fighting Covid you have risen to that challenge – with abundant energy, intelligence and determination that are your hallmark.
‘You should be immensely proud of your service. I am grateful for your support and believe your contribution to public service is far from over.’
But on Friday afternoon, a spokesman from Downing Street had said that Mr Johnson had accepted an apology from Mr Hancock’s and ‘considered the matter closed’.
Gina Coladangelo is leaving her post in Department of Health, according to the BBC’s political editor, Laura Kuenssberg.
Portsmouth South MP Stephen Morgan has called for an investigation into the shamed former health secretary’s conduct.
He said: ‘Reports (on Friday) suggest he has failed to declare that he was engaged in a relationship with someone who he personally appointed at taxpayers’ expense to serve as an adviser, and subsequently a non-executive director, at the Department of Health and Social Care.
‘This would appear to be yet another breach of the Ministerial Code and the government’s Independent Adviser on Ministers’ Interests should immediately investigate the health secretary’s conduct, and his apparent breach of the Ministerial Code.’
Commenting earlier today before the resignation, Portsmouth North MP Penny Mordaunt said people felt disappointed and ‘let down’ by Mr Hancock.
Ms Mordaunt, who is currently isolating at home, said: ‘I understand how annoyed people are – everyone has worked so hard and given up so much to beat coronavirus.
‘I have always said that we all have to stick to the rules laid out by the government.’