The BBC is to appoint external investigators to assess the impartiality of its coverage of contentious topics.

The corporation’s director general, Tim Davie, announced on Friday the BBC’s entire output – including children’s programming, documentaries and educational material – will in the future be constantly analysed for any impartiality breaches as part of a series of rolling external investigations.

Programme makers in all areas of the BBC’s output, not just the news division, will be required to show they are representing a broad range of ideologies and voices in their content. This means everything, from CBeebies to BBC Sport and the corporation’s social media accounts, is likely to be scrutinised to make sure it is reflecting a variety of viewpoints.

The BBC said the new impartiality assessment process would challenge “underlying assumptions and groupthink” in the organisation, echoing comments made earlier this month by the culture secretary, Nadine Dorries, who told the BBC to stop being so liberal and London-centric. The BBC is currently struggling to secure a new licence fee settlement with ministers.

Each impartiality review will have an externally appointed chair and will seek evidence from the public and interested organisations on how the BBC covers a particular contentious national topic, giving lobby groups an opportunity to formally attempt to influence the broadcaster’s editorial line.

BBC director general Tim Davie.

The choice of external individuals to lead each review – and whether they have any political connections – is likely to come under intense scrutiny, given the government’s willingness to push its own preferred candidates for cultural appointments. Ministers are already taking an active interest in who the corporation will appoint as the new head of news and the potential replacement for Laura Kuenssberg as political editor.

The first review will look at how the BBC reports on UK public spending and taxation. How the corporation frames this topic is highly contentious. On Wednesday the main BBC News Twitter account deleted a post stating that the chancellor, Rishi Sunak, now “has to balance the books” because he borrowed heavily during the pandemic, amid complaints that the broadcaster was effectively endorsing the government’s arguments on public spending.

BBC journalists are already speculating as to which other contentious topic areas are likely to be the subject of future external impartiality reviews. Culture war issues, trans rights and immigration are often among the matters that attract most feedback from the public and could be potential candidates for investigation.

The recommendation to launch the impartiality reviews was made by a review of BBC editorial standards led by the Arts Council England boss, Sir Nicholas Serota, with assistance from BBC board members Ian Hargreaves and Sir Robbie Gibb.

Although the Serota-led report was originally set up in response to the historic scandal over Martin Bashir’s 1995 mishandled interview with Diana, Princess of Wales, its recommendations are far broader in scope and are likely to have enormous impact on how the BBC operates in the modern era.

Davie, who unlike most of his predecessors as director general has never worked as a journalist, has put enforcement of impartiality at the heart of his pitch to secure the future of the corporation.

Yet exactly what counts as impartiality and whether it is possible to define it for each issue is an increasingly sensitive topic for the publicly funded broadcaster. Coherent enforcement across the BBC’s sprawling array of television channels, radio stations and websites is even harder.

Topics such as whether the climate crisis is real or whether homophobia is wrong are considered to be beyond debate within the newsroom. But other issues – such as campaigning for transgender rights and public support for anti-racism campaigns – can be internally seen as political issues that may breach impartiality rules.

The BBC has said each external impartiality review will be encouraged to take evidence from the public and interested organisations, meaning lobby groups will be able to submit their assessments.

The impartiality reviews will be asked to consider the “language and tone” of BBC programming for evidence of excessive bias, whether the corporation is consistent in its approach to topics, or whether certain viewpoints are systematically excluded from coverage. The BBC also said it would increasingly look to address the issue of impartiality in a broader sense rather than focus on traditional left-wing v right-wing political debates.

Each review will also result in a written external assessment of what BBC impartiality means for coverage of a particular topic area, making it easier for external organisations to complain that the BBC is breaching its own guidelines.