Ofcom has said that the conclusions of ongoing investigations that look into episodes of current affairs programmes presented by MPs will set a “precedent for other editors”.

At a meeting of the Culture, Media and Sport committee on Tuesday to scrutinise the Draft Media Bill, the media watchdog was grilled by SNP MP John Nicolson.

Ofcom was asked why it is not taking more action on sitting politicians fronting current affairs programmes.

MPs who present shows on radio and TV include Lee Anderson, vice chairman of the Conservative Party, on GB News, and Labour’s shadow foreign secretary David Lammy, on LBC.

Kate Biggs, Ofcom content policy director, said the media watchdog takes its responsibility on impartiality and accuracy rules “very seriously”.

She added: “We need to take these investigations thoroughly (and) make (a) decision known publicly, because they do set a precedent for other editors.”

On Monday, Ofcom announced an investigation into an episode of Sir Jacob Rees-Mogg’s GB News show which addressed a court case involving former US president Donald Trump.

The media watchdog will look at whether the State Of The Nation show abided by guidelines which prevent politicians from acting as a newsreader unless it is  “editorially justified”.

An episode of Talk TV’s Richard Tice show, presented by the leader of the Alba Party Alex Salmond, is also being investigated.

The media watchdog is already looking at an edition of GB News’ Saturday Morning With Esther And Philip.

The programme, which stars husband-and-wife duo and serving MPs Esther McVey and Philip Davies, is being investigated over whether it breached impartiality rules after airing an interview with Chancellor Jeremy Hunt ahead of the spring Budget.

Mr Nicolson also asked Ofcom why more GB News programmes presented by Sir Jacob have not been investigated.

Ms Davies said: “We look at every single complaint in the same way, either (an) individual complaint or multiple complaints.

“We look at them in relation to our rules and take a decision whether to investigate or not.”

She also told the committee: “The media landscape has evolved, significantly, I think there has been a long tradition of personality-based presenters but… there’s more.”

In 2005, rules surrounding politicians presenting programmes were first introduced.

The media watchdog has said it is conducting new research to “gauge current audience attitudes” into current affairs programmes presented by sitting politicians given the rise in the format.

This report will be carried out by an research agency and Ofcom aims to publish the findings later this year.