Ofcom has warned broadcasters using politicians as presenters that “the highest level of due impartiality applies during election periods” and breaches could result in “statutory sanctions”.

The regulator’s updated guidance comes after it found GB News in breach of broadcasting rules when three Conservative MPs acted as newsreaders across five different episodes of its programmes.

Ofcom’s probe involved shows presented by former House of Commons leader Sir Jacob Rees-Mogg, as well as minister without portfolio Esther McVey and backbencher Philip Davies, and the channel was warned about potential sanctions if there are further breaches.

Married couple Ms McVey and Mr Davies are no longer part of the GB News line-up.

Ofcom warned it is putting broadcasters “on notice to maintain due impartiality ahead of the general election”.

A statement said: “Broadcasters are reminded that Rule 6.6 of the Code prohibits candidates in UK elections from acting as news presenters, interviewers or presenters of any type of programme during the election period.”

Under current rules politicians are allowed to present current affairs show but not act as newsreaders, and the rules are tightened in the run-up to an election.

Ofcom said: “With a general election due to take place before 25 January 2025, we are sounding a warning to broadcasters to maintain the highest level of due impartiality, in line with our enhanced rules that apply during election periods.

“Any breaches of election programming rules are likely to be serious and to result in Ofcom considering the imposition of statutory sanctions.”

New audience research by the regulator found that while there are “concerns” about politicians presenting current affairs programmes, there is “no clear consensus for an outright ban”.

Updated guidance reinforces the prohibition on politicians presenting news and “reminds broadcasters that, because politicians have an inherently partial role in society, news content presented by them is likely to be viewed by audiences in light of that perceived bias, which would risk undermining the integrity and credibility of broadcast news”.

The guidance does state that broadcasters “retain editorial freedom to create programmes which move between news and current affairs content” but cautions that is a politician is a the host of a programme “they must ensure they do not act as a newsreader, news interviewer or news reporter at any point in that programme”.

On Tuesday former GB News chairman Andrew Neil said Ofcom needs to “grow a backbone and quick” over the issue of politicians hosting TV programmes.

He told peers: “It may be because the rest of the broadcast universe is on the centre, centre-left so it gave GB news a bit more leeway to settle down.

“I am surprised that any regulator would allow politicians sitting in the Houses of Parliament to present political TV programmes.

“If I had stayed as chairman it would not have happened because I would not have had any politician present a TV show in the first place, and I would certainly never have allowed politicians to interview politicians from the same party.

“I just find that incredible and I think on these areas Ofcom needs to find a backbone and quick.”

After Ofcom issued its warning on Wednesday, the host of BBC Radio 4’s Today programme, Nick Robinson, questioned the media watchdog’s parameters on impartiality.

In a post on X, formerly Twitter, he wrote: “So, @Nigel_Farage – one of the founders & owners of @reformparty_uk – can present an ‘impartial’ programme on a TV ‘news’ channel during the general election according to the broadcasting regulator @ofcom.

“The leader of the party @TiceRichard & its only MP @LeeAndersonMP_ can present programmes in the run up to the campaign alongside @Jacob_Rees_Mogg.

“Is that your idea of impartiality?”