Relations between Boris Johnson and Channel 4 News have hit a new low after the PM scrapped a planned interview just days after the channel’s chief accused him of being a “coward”.

Insiders at Channel 4 News were left furious when Johnson ditched an interview less than 24 hours before presenter Matt Frei had been due to sit down with him at the G7 summit in France.

Frei had travelled to Biarritz specifically to quiz the prime minister along with the BBC, ITV and Sky News, and logistics had been put in place to arrange the interview for Sunday morning.

Johnson suggested that he had committed instead to talking to French media, but Channel 4 sources told HuffPost UK that it was a clear decision to refuse the channel in retaliation for recent remarks by news and current affairs chief Dorothy Byrne.

It is understood that journalists at the channel were told Bryne had “crossed the line” by recently comparing Johnson to Vladimir Putin for his failure to grant live TV interviews.

Speaking at the Edinburgh TV Festival last week, Byrne had said the British leader was like the Russian president because of his preference for a “jolly statement” over a grilling on television. 

She added: ”What we all need to decide: what do we do when a known liar becomes our Prime Minister?

“I would never have thought I would say these words: I believe that Mrs Thatcher would agree with me; Boris Johnson and Jeremy Corbyn are cowards. She had a word for men like them – ‘frit’.”

One Channel 4 source said the decision by No.10 was “Trump-esque”. “It felt a little like bullying,” they added.

Channel 4 News’ editor Ben de Pear said he would be “looking for clarity” over the decision, but claimed government advisers had decided that “C4 criticism of lack of access had resulted in…no access”.

Johnson was directly challenged on the row by ITV’s Robert Peston, who said he was not allowing himself to be “held to account”.

Asked by Peston why he had pulled out of the Channel 4 grilling, Johnson said: “I’m delighted to be interviewed by you Robert, it’s the highest honour that, one of the high honours that a politician can have.

“But I have to, I’m afraid, once this ceremony is over, I have to go and talk to French radio, French TV and lots of other outlets as well.”

Peston then tweeted that he had suggested to Johnson that he had “shot himself in the foot” in his response to Byrne.

″‘Not in the least’ he told me. But if he heard Byrne’s recent MacTaggart speech and a linked interview as undermining Ch4′s impartiality, surely he should complain to the regulator Ofcom.

“Ofcom would be the appropriate adjudicator. And at a time of what Johnson calls a national emergency, he should not shy away from scrutiny by Ch4 or any serious news organisation.”