Sky News has pulled out of an interview with Boris Johnson after its political editor, Beth Rigby, was told she could not make an audio recording or transcript of the talk.

The former prime minister had promised to “reveal what really happened during my time as [London] mayor, foreign secretary and PM” during the conversation next week as he promotes his memoir Unleashed. Johnson’s interview with the BBC was dropped earlier this week after the presenter Laura Kuenssberg mistakenly sent him her briefing notes.

In a post on X on Friday, Rigby said: “I was looking forward to interviewing Boris Johnson at Cheltenham but regrettably I can’t go ahead with the event because I am not allowed [to] make an audio recording or transcript of the interview.

“As a journalist in conversation with a former PM at a public event, I can only proceed if we do it on the record. I’m sorry to have to pull out.”

On Wednesday, Kuenssberg said she had sent Johnson the notes for her interview “in a message meant for my team”, and cancelled the discussion with the former Conservative party leader.

The BBC’s former political editor said the error was “embarrassing and disappointing”, and meant it was “not right for the interview to go ahead”.

In an interview with ITV News broadcast on Friday night, Johnson said he regretted apologising over his government’s lockdown parties in Downing Street in 2020. In his memoir, he wrote that he made a “mistake” issuing “pathetic” and “grovelling” apologies over partygate, which he said “made it look as though we were far more culpable than we were”.

Tom Bradby, who presents ITV News at Ten, asked Johnson: “You basically say: ‘It wasn’t a big deal. I regret apologising.’ Is that really your position? Did you regret apologising to the queen?”

Johnson refused to answer and replied: “I don’t discuss my conversations with the queen.”

He added: “What I was trying to say there was, I think that the blanket apology – the sort of apology I issued right at the beginning – I think the trouble with it was that afterwards, all the accusations that then rained down on officials who’d been working very hard in No 10 and elsewhere were thought to be true.

“And by apologising I had sort of inadvertently validated the entire corpus and it wasn’t fair on those people.”

The memoir also claimed that Gavin Williamson blocked a £400m deal to bring the British-Iranian prisoner Nazanin Zaghari-Ratcliffe home from Iran five years before she was released, on the basis the money could be used by Hezbollah.

Johnson said that in 2017 he reached an agreement for the dual national’s release in return for money owed by Britain to Tehran since the 1970s. The Treasury and the Foreign Office approved, but No 10 insisted the decision needed to be signed off by all relevant departments, including the Ministry of Defence, which at the time was headed by Williamson.