She is Britain’s best known classicist, a Cambridge don with formidable intellect and a knack for getting people interested in all things ancient.

That combination of passionate erudition and accessibility would, you might think, make Mary Beard a shoo-in for the board of the country’s most prestigious historical institution.

You would be wrong. The 65-year-old scholar has been rejected by Downing Street as a trustee of the British Museum, the Observer understands. Whitehall sources said the decision last year to turn her down had been made because of her pro-European views, which she has frequently expressed via social media.

Now, in response to the first rejection of a proposed British Museum trustee by No 10 for many years, the museum is understood to be planning to take matters into its own hands and appoint Beard without the lengthy and sometimes byzantine process of the Whitehall system.

Under the current arrangement, Downing Street has a say over the appointment of most of the museum’s 25 trustees, but the museum’s constitution allows it to choose five for itself. “Good for the trustees,” said one longstanding former board member, who did not want to be named. “The decision to reject her is more about political correctness than respected classical scholarship.”

Sir John Tusa, another former trustee and also former BBC World Service boss, said: “This is an absolute scandal. The trustees of the British Museum exist to protect its intellectual, academic and political independence. Government interference in putting in placemen or placewomen is a corruption of public life. Will any Remainer now expect to be punished by the government?”

This weekend, Beard, who in 2018 said she had fulfilled “a lifetime’s ambition” by working for a day as a visitor attendant at the museum, said that “if asked” to serve she would “do my duty”. But she cautioned: “Being a good girl does not mean being a lackey.”

The decision to reject her is more about political correctness than respected classical scholarship Former board member

Asked why she thought she had been rejected earlier, Beard, who most recently presented the Shock of the Nude on BBC2, replied: “There are cock-ups and conspiracies. I’m not, however, going to diss Boris Johnson or the Department of Culture.”

The decision to turn down Beard is believed to have happened at the end of Theresa May’s premiership, when the museum proposed four new candidates for its board. Three were accepted, all from the worlds of business and finance. It is understood that the museum, noting that Beard was not among the names appointed by No 10, then made some discreet inquiries before eventually being told that the Brexit-embattled government did not appreciate her pro-EU social media remarks.

Beard has never hidden her stance on the UK’s departure from the EU. But she would hardly be the only trustee to have made public statements that could be seen as political. Grayson Perry, on the board since 2015, has expressed both his support for the Labour party and Remain.

The museum, which declined to comment last night, is understood to be upset because the rejection of Beard seems to contradict its longstanding relationship with government, which has always been at “arm’s length”. While it gives the museum £40m of funding a year, the government does not interfere in its running, exhibitions or the selection of its director, who is currently the German-born Hartwig Fischer.

The museum’s new attempt to appoint Beard comes with a very different prime minister. Boris Johnson is also a classicist, even if one not quite in the same league as Beard.

Four years ago, Johnson and Beard faced each other in a debate organised by the media events company Intelligence Squared. Johnson took the Greek side while Beard argued for the Romans. Before the discussion, the audience voted that Greece had given more to civilisation. But during the discussion, in which the then mayor of London called the Romans “a very nasty bunch”, Beard gradually swayed the audience, and, at the end, a vote was taken, with a victory for the Romans and Beard.

Johnson famously has a bust of the Greek statesman Pericles in his No 10 office – itself, ironically, a copy of an original in the museum. He also owns socks depicting the Assyrian king, Ashurbanipal, bought from the museum’s shop last year during an Assyrian exhibition. Ashurbanipal called himself “king of the world” – a view echoed by the young Johnson, who told his family as a child that he planned to be “world king”.

Downing Street declined to comment on the matter.