GB News has lost a High Court bid to temporarily block Ofcom from sanctioning it after the regulator claimed that a Q&A with Rishi Sunak broke impartiality rules.

The channel asked a judge to order that Ofcom could not complete its “sanctions process” amid a legal challenge over the regulator’s finding that the show with the then-prime minister in February breached its code.

Barristers for GB News said that the publication of the sanction would cause “irreparable damage” to its reputation, but in a ruling on Friday Mr Justice Chamberlain said that the “likely impact” on the channel had been “overstated”.

There is significant public interest in allowing Ofcom to complete its process and publish its decision

But he gave the channel the green light to challenge the finding that it had breached Ofcom’s rules in the High Court, and added that Ofcom has already pledged not to publish its sanction until the case had been heard.

Giving judgment at a hearing in London, the judge said: “There is significant public interest in allowing Ofcom to complete its process and publish its decision.”

He continued that the benefits of pausing the sanctions process were “firmly outweighed” by allowing it to continue, which he said would “promote public confidence” and “reinforce the importance of complying with the code”.

But he said that GB News’s case was “reasonably arguable” and its arguments “raise grounds of considerable public importance” which “should be considered at a substantive hearing”.

Ofcom began an investigation into GB News three days after the airing of a programme titled People’s Forum: The Prime Minister, which saw Mr Sunak answer questions from a studio audience and a presenter.

In a statement on its website on May 20, Ofcom said that it had reached a provisional view the programme “broke broadcasting due impartiality rules” and that it was a “serious and repeated breach” of its rules.

The regulator said that it received 547 complaints about the hour-long programme and that it found that the programme had not “challenged (Mr Sunak) or otherwise referred to significant alternative views”, and that GB News should have “taken additional steps” to ensure impartiality.

It added that it was “starting the process for consideration of a statutory sanction” against GB News, with potential sanctions including fines, directions not to repeat content or to broadcast a correction, and suspending licences.

Tom Hickman KC, for the channel, said on Thursday that the regulator had unlawfully found that the breach was “serious and repeated”, and that deciding on and publishing a sanction during the legal challenge would cause “irreparable damage”.

We believe some of (Ofcom's) decisions in relation to GB News have been neither fair nor lawful and the court has recognised that there are serious arguable issues to be determined in this respect

Anya Proops KC, for Ofcom, said in written submissions that the breach was the channel’s 12th since March last year and that it was “not arguable” that it had “erred in law” through its decision.

She continued that the bid to stop Ofcom from publishing the sanction was based on an “inevitably speculative presumption” of what the sanction would be, and that claims the channel would suffer reputational harm “do not withstand scrutiny”.

A further hearing in the case is expected to be held at a later date.

Following the judgment, GB News chief executive Angelos Frangopoulos said the channel was “extremely pleased” with the ruling.

He said: “We have believed from the very start that the People’s Forum was an important piece of public interest programming, and that it complied with the Broadcasting Code.

“It was designed to allow members of the public to put their own questions directly to leading politicians.

“The programme with the prime minister was always intended to be part of a series of programmes, unfortunately the commencement by Ofcom of an investigation into the programme meant that future programmes were suspended and could not be broadcast.

“GB News chooses to be regulated and we understand our obligations under the code, but Ofcom is obliged by law to uphold freedom of expression and apply its rules fairly and lawfully.

“We believe some of its decisions in relation to GB News have been neither fair nor lawful and the court has recognised that there are serious arguable issues to be determined in this respect.”

A spokesperson for Ofcom said: “We are pleased that the court has rejected GB News’ attempt to suspend the sanctions process, and has recognised the significant public interest in Ofcom completing it.”