Jenna Coleman will reportedly be “leaving Doctor Who” after snapping up the lead in a new ITV drama.

The actor, who plays the Doctor’s assistant Clara Oswald, will be time-travelling back to the 19th century to play Queen Victoria in a new eight-part £10m drama, according to the Mirror.

Coleman, 29, is thought to have already filmed her final scenes alongside Peter Capaldi and she will leave before the Doctor Who Christmas special.

She has played Clara in the BBC sci-fi series for three years and accompanied actors Matt Smith and Capaldi on their adventures as the Doctor. Coleman is now the longest-serving assistant since the series was relaunched in 2005.

This week, Coleman told the Radio Times that she did not know how long she would last in the series.

“You’re in Doctor Who knowing it will never last. It’s constantly regenerating, so you want to make your time count and enjoy the adventure for the fleeting time you’re here,” she said.

The new ITV epic, called Victoria, will follow the early life of Queen Victoria from the time she assumed the throne at the age of 18.

The series is written by novelist Daisy Goodwin and based on Queen Victoria’s diaries – all 62m words of them. Goodwin said that her writings gave “an astonishingly vivid picture of her transformation from a rebellious teenager”.

ITV have said that Victoria will film in locations across the UK from September.

Doctor Who have said there is “no comment” on the reports.

The new series of Doctor Who returns to BBC1 on 19 September.