Matt Hancock has said he resigned as health secretary after colleagues failed to defend him publicly following the disclosure he was having an affair with an aide.

In the latest extract of his diary, serialised by The Mail+, Mr Hancock said Boris Johnson had assured him he could carry on even though he and Gina Coladangelo had been pictured kissing in his office in breach of his own social-distancing guidelines.

But after the story broke in The Sun last year, he said he found himself “increasingly isolated” politically and was left with no choice but to quit.

Mr Hancock also disclosed that his final resignation statement was filmed by Mr Johnson on a mobile phone. He said he had to do repeated takes because the camera was waving up and down so much.

The publication of his Pandemic Diaries coincides with his return to Westminster from Australia following his controversial spell on ITV’s I’m A Celebrity … Get Me Out Of Here!

In it, Mr Hancock records how, on Thursday June 24 2021, he went to see Mr Johnson in Downing Street to tell him The Sun was about to publish details of his affair.

He said the paper was accusing him of bringing Ms Coladangelo into his department because of their affair – which he said was untrue – and of breaching Covid guidance on social distancing.

Mr Johnson replied: “Well, you haven’t broken the law. The guidelines aren’t binding – they’re recommendations. So I will stand by you.”

However, by the weekend he realised that his position was becoming untenable.

“Privately, I was still getting positive messages from colleagues. Publicly, few were willing to defend me. Politically, I was increasingly isolated,” he wrote.

“I went to Chequers to see the PM. I explained that I had been thinking about what had happened and how it had made people feel – and that my mind was made up. The damage to my family and to the Government was too great.

“I told Boris I had to resign.”

Mr Hancock also described that farcical scene in the garden of Chequers – the prime minister’s official country residence – as they tried to film his resignation statement.

“In the end, the great machinery of the State was nowhere. It was just me and the PM fumbling around with an iPhone. He stood on the grass, holding the phone while I said my piece. It took a few goes to get it right,” he wrote.

“He nodded sympathetic encouragement so much throughout the first take that the camera waved up and down. In the end it wasn’t perfect, but I was beyond caring: I had to get it out.”