Boris Johnson and figures linked to him are engaging in an effort to undermine the BBC’s leadership, insiders fear, after the leaking of a memo criticising its reporting of Donald Trump, trans rights and Gaza.

Tim Davie, the BBC’s director general, and other senior editorial staff are under pressure after the criticisms made in the document by Michael Prescott, a former independent external adviser to its editorial guidelines and standards committee (EGSC).

Parliament’s culture, media and sport committee has demanded to know the BBC’s response to the memo, setting Monday as a deadline. The BBC’s board is compiling its response.

Advertisement However, insiders believe the leaking of the memo to the Daily Telegraph and the criticisms that have followed from Johnson are part of a concerted attempt to undermine the organisation, which is heading into crucial talks with the government over the renewal of its charter.

Johnson told the Telegraph that Davie “must either explain or resign” over the claims in the memo. He said the BBC had been “caught red-handed in multiple acts of leftwing bias”.

Concerns have previously been raised about the role of Robbie Gibb, who joined the BBC board when Johnson was in Downing Street.

Gibb was Theresa May’s communications director during her tenure as prime minister and helped launch the rightwing news channel GB News.

Sources have told the Guardian that Gibb was instrumental in the appointment of Prescott as an adviser to the EGSC. They have previously been reported as being friends. Prescott left his BBC advisory role in the summer.

Johnson said the idea there was an effort to undermine the BBC’s leadership was “complete and utter bollocks”.

Advertisement “I haven’t spoken to either individual [Gibb or Prescott] – or been in contact with either of them in any way – for many years,” he said.

“The first I heard of Michael Prescott’s report was when I saw it on the Telegraph website. The Panorama fabrication is scandalous. Why don’t you try to establish how and why that happened rather than making up more mad lefty nonsense?”

Gibb was approached for comment, but referred the Guardian to the BBC. A BBC spokesperson said: “The BBC board is made up of 13 members, five of whom are appointed by government including Sir Robbie Gibb.

“The editorial guidelines and standards committee is not involved in day-to-day output. It looks at editorial matters post-broadcast, including complaints.

“[The editorial adviser roles] were advertised externally as part of the BBC’s open and fair competition process, and Michael Prescott was interviewed by a panel of board members who made the collective decision to appoint him.”

Gibb was on the four-person panel that interviewed Prescott for the role.

Advertisement Prescott was also contacted for comment.

In his memo, reported by the Telegraph, Prescott states: “I have never been a member of any political party and do not hold any hard and fast views on matters such as American politics or disputes in the Middle East. My views on the BBC’s treatment of the subjects covered below do not come with any political agenda.”

Prescott is now preparing to appear before the Commons culture, media and sport committee soon.

Rupa Huq, one of the MPs on the committee, said this kind of appearance was not normal. She tweeted that it was “highly unusual for one person panels, particularly when they are partisan figures”.

A lot will now rest on the response of the BBC’s board, of which Gibb is also a member. There are some concerns among people close to the BBC that the board was set up to boost the BBC’s commercial activities, rather than to be expert on editorial issues.

Some figures concerned about the criticisms of the BBC believe they are linked to attempts, dating back to Johnson’s time in charge, to pull the media to the right.

Advertisement Prescott’s memo has already led to criticism from senior Conservatives. The Tory leader, Kemi Badenoch, said “heads should roll” at the corporation. Johnson posted on social media last week: “Is anyone at the BBC going to take responsibility – and resign?”

The main criticism of Prescott’s memo focused on an edition of Panorama, broadcast a week before the US election. He accused the BBC of selectively editing a Donald Trump speech to make it appear clearer that he encouraged the US Capitol attack.

A spliced clip suggested that Trump told the crowd: “We’re going to walk down to the Capitol and I’ll be there with you, and we fight. We fight like hell.” The words were taken from sections of his speech almost an hour apart.

Prescott also raised concerns about BBC Arabic. He claimed that a review by the BBC journalist David Grossman had highlighted “systemic problems within BBC Arabic” that represented anti-Israel bias. He added that insufficient action had been taken after Grossman’s report.

This is disputed. Minutes of a meeting of the EGSC in March, in which the findings of Grossman’s report were discussed, state that “important structural and management changes had recently been made to the oversight of World Service operations, including BBC Arabic. In response to the report a number of additional actions had been implemented.”

A BBC spokesperson said: “With regard to BBC News Arabic, where mistakes have been made or errors have occurred, we have acknowledged them at the time and taken action.

Advertisement “We have also previously acknowledged that certain contributors should not have been used and have improved our processes to avoid a repeat of this.”

The BBC said it had already stopped featuring figures cited by Prescott as expressing antisemitic views.

In 2021, the Johnson government was accused of creating a conflict of interest after appointing Prescott to help select the next chair of Ofcom, the UK’s media regulator. He was appointed as a senior external interviewer for the role. The Johnson government had been pushing for the Ofcom job to go to Paul Dacre, the former editor of the Daily Mail.

Tim Davie The Tube presenter, the former ballerina and the banker: the BBC board’s members Read more At the time, a government spokesperson responded on Prescott’s behalf to say: “The recruitment process for the Ofcom chair is fair and open and there are no conflicts of interest. Mr Prescott’s role on the panel has been approved by the independent commissioner for public appointments.”

Gibb has previously been accused of attempting to block a senior editorial appointment on political grounds. He was accused of trying to stop Jess Brammar, the former editor of HuffPost UK and deputy editor of BBC Newsnight, from a role overseeing the BBC’s news channels.

A BBC spokesperson said at the time that “as a general principle, board members are able to discuss issues with other board members or senior executives. These principles were adhered to”.