Three Tory MPs who “acted as newsreaders” across five different episodes while being the lead presenter of their GB News programmes have been found to have broken broadcasting rules on due impartiality.

Ofcom’s probe involved various shows that were presented separately by former House of Commons leader Sir Jacob Rees-Mogg, and minister without portfolio Esther McVey and backbencher Philip Davies.

The channel was also warned about potential sanctions if there are further breaches.

GB News said that it is “deeply concerned” by Ofcom’s ruling and will meet with the media watchdog to raise concerns about the “chilling development”.

A further episode of Sir Jacob’s State Of The Nation was not investigated because it did not raise issues under the rules, according to Ofcom.

Married couple Ms McVey and Mr Davies are no longer part of the GB News line-up, and last hosted programmes on the channel last year.

Their breaches involved Sir Jacob talking on May 9 about a verdict involving former US president Donald Trump’s civil trial and Ms McVey and Mr Davies speaking on May 12 about train strikes, the UK economy, a court case involving the Duke of Sussex and a teenager who was being sentenced for terrorism offences.

On May 12, Saturday Morning With Esther And Philip interviewed Reform UK candidate Howard Cox about a “developing news story”, namely the anti-Ulez protest rally on and a Friday edition on June 23 – which covered the doctor’s strike – were also found to have breached the rules.

Ofcom cited Sir Jacob on June 13 talking about a stabbing incident in Nottingham as another example.

The watchdog said: “We found that two episodes of Jacob Rees-Mogg’s State Of The Nation, two episodes of Friday Morning With Esther And Phil, and one episode of Saturday Morning With Esther And Phil, broadcast during May and June 2023, failed to comply with Rules 5.1 and 5.3 of the Broadcasting Code.”

Ofcom said that because the politicians “acted as newsreaders, news interviewers or news reporters in sequences which clearly constituted news – including reporting breaking news events – without exceptional justification, news was, therefore, not presented with due impartiality”.

It went on: “Politicians have an inherently partial role in society and news content presented by them is likely to be viewed by audiences in light of that perceived bias.

“In our view, the use of politicians to present the news risks undermining the integrity and credibility of regulated broadcast news.”

We are deeply concerned by the decisions Ofcom has made today. We will raise this directly with the regulator in the strongest possible terms

Ofcom has put GB News on notice that any repeated breaches of the same rules “may result in the imposition of a statutory sanction”.

This could mean the channel being fined up to the maximum financial penalty of £250,000 or 5% of the broadcaster’s revenue, or having its licence shortened or revoked along with having to broadcast a correction or not to re-air the programme.

This is the first time the broadcaster broke these rules, according to the watchdog.

In a statement, GB News said: “We are deeply concerned by the decisions Ofcom has made today.

“We will raise this directly with the regulator in the strongest possible terms.

“Ofcom is obliged by law to promote free speech and media plurality, and to ensure that alternative voices are heard.

“Its latest decisions, in some cases a year after the programme aired, contravene those duties.”

GB news claimed that Ofcom has “arbitrarily changed the test” and this ruling was a “chilling development for all broadcasters, for freedom of speech, and for everyone in the United Kingdom”.

It said it “takes its obligations very seriously” and is committed to having politicians as presenters on the channel.

Ofcom said that the Tory MPs delivered “factual” statements on air but the concerns were that politicians acting as newsreaders is against due impartiality.

Earlier this month, Ofcom also found that GB News broke broadcasting rules when actor turned campaigner Laurence Fox made comments which the watchdog said constituted a “highly personal attack” on a female journalist, Ava Evans.

The media watchdog said it had found Fox’s comments to be “degrading and demeaning both to Ms Evans and women generally” and “clearly and unambiguously misogynistic”.

In December, the network’s Don’t Kill Cash campaign was found to have broken due impartiality requirements.

Ofcom said all broadcasters’ programmes must “exclude all expressions of the views and opinions of the person providing the service on matters of political or industrial controversy or current public policy”.

There are eight open investigations into GB News programmes currently.

These include a special called the People’s Forum: The Prime Minister, where Rishi Sunak took questions from the public in a live Q&A, an episode of former Ukip and Brexit Party leader Nigel Farage’s programme on the channel on January 17, and an edition of the breakfast show with ex-This Morning presenter Eamonn Holmes and former Sky News presenter Isabel Webster.

GB News has been found to have been in breach 11 times, including when Ms McVey and Mr Davies interviewed Conservative MP and Chancellor Jeremy Hunt about the Budget in a pre-recorded programme, which aired on March 11 2023.

An installment of GB News Radio on March 2 2022 also did not follow the rules, Ofcom said.