“We need more voices on telly – there’s not enough working-class people in telly and not enough diversity,” said UKTV head of comedy entertainment Iain Coyle.

“All the different voices that make up this country need to be working in television – not just the poshos who’ve been to Cambridge and Oxford,” said Sohail Shah, the MD of new indie King of Sunshine Productions.

He added: “Without new talent you don’t get any kind of progression in TV.”

Graham, who founded the programme’s producer Wall to Wall, came up with the idea for a genealogy series in which famous faces discover the truth about their ancestors – but it took a decade and a half for a commissioner to bite.

“This show is 15 years old this year but this year is also the 30th anniversary of me trying to sell it to the BBC,” he said.

Who Do You Think You Are?

Monday: BBC One, 9pm

Versailles

Monday: BBC Two, 9pm

This year’s line-up of history hungry stars includes British actress and newly minted star of The Crown Olivia Colman (Broadchurch), pop icon Boy George, comedian Lee Mack, former JLS member Marvin Humes and Our Girl actor Michelle Keegan.

Olivia Colman will journey from Norfolk to India, embarking on the discovery of a diverse heritage and Lee Mack’s investigation uncovers that comedy runs in the family.

The series covers almost a thousand years of history, from the invention of the weekend to the arrival of the first pineapples in Britain.

From Danny Dyer’s royal connection to singer Cheryl’s First World War hero, the show promises to discover some surprising stories in the family trees of the celebrities.

The twelfth series of the genealogy programme will touch on almost a thousand years of history from the Tower of London to the Punjab in India, via the Wild West of the US.

Actor Sir Derek Jacobi uncovers a background of contrast, from humble roots in Walthamstow to the excesses of Louis XIV's royal court in France, while model Jerry Hall traces her pioneering ancestors from the cotton mills of Oldham to the plains of Texas.