The outgoing boss of Britain's BBC sought to rally his journalists on Tuesday, saying that although they had made mistakes they needed to fight for their work as the broadcaster confronts legal action by US President Donald Trump.

The British Broadcasting Corporation has been plunged into its biggest crisis in decades after its two most senior staff, Director General Tim Davie and head of news Deborah Turness, quit following criticism over bias at the corporation, including in the way it had edited a speech by Trump.

Davie told staff that he was fiercely proud of the publicly funded organisation, while acknowledging that "we have made some mistakes that have cost us".

"We are a unique and precious organisation, and I see the free press under pressure, I see the weaponisation," he said at an all-staff meeting, without elaborating.

Analysts say the resignations have exposed deep frictions over governance and editorial standards at the broadcaster, raising questions about whether it can maintain public trust.

An internal memo by a former BBC adviser accused it of editorial failings on Trump, the Israel-Hamas war and transgender coverage.

But Davie, who became director general in 2020, tried to calm worries over the broadcaster's future.

"The BBC is going to be thriving, and I support everyone on the team," he said ahead of the all-staff meeting.

Davie said he had decided to step down because of the job's relentlessness, the need to give his successor time to prepare for the next review of the BBC's funding model, and an editorial breach that required accountability, according to a transcript of his comments at the staff meeting.

The outgoing boss said he was proud of the team he had built, adding that "some responsibility had to be taken" for mistakes made. He added that the BBC would "survive" his departure and thanked staff for their work.

Critics have accused the BBC of failing to uphold impartiality, citing the edit of a speech made by Trump in 2021 on the day his supporters overran the Capitol as part of a wider pattern.

BBC chair Samir Shah apologised for the "error of judgement" in the edit included in a Panorama documentary aired shortly before the November 2024 US presidential election.

The BBC, founded in 1922 and funded largely by a licence fee paid by all TV-owning households, is now without a permanent leader as it faces a government review of the terms of its charter and funding model.

The current 10-year charter expires in 2027.

Prime Minister Keir Starmer on Monday rejected suggestions that the BBC was "corrupt" or "institutionally biased" and stressed the need for it to maintain high standards. (Reuters)