New Doctor Who star Pearl Mackie will play the sci-fi series’ first openly gay companion, the actress has revealed.

"Yeah, Bill's gay. It shouldn't be a big deal in the 21st Century. It's about time isn't it?" Mackie, who will play Bill Potts in the new series, told the BBC.

"That representation is important, especially on a mainstream show."

Doctor Who has previously featured gay or bisexual characters like John Barrowman's Captain Jack Harkness, Neve McIntosh's Vastra and Alex Kingston's River Song, but Bill's sexuality will mark the first time the series' main companion has been depicted as gay.

According to the BBC Bill's sexuality will be referenced early on in her first episode, in the character's "second line of dialogue".

"It's important to say people are gay, people are black – there are also aliens in the world as well so watch out for them," Mackie continued.

"I remember watching TV as a young mixed race girl not seeing many people who looked like me, so I think being able to visually recognise yourself on screen is important."

"[Being gay] is not the main thing that defines her character – it's something that's part of her and something that she's very happy and very comfortable with."

Doctor Who returns to BBC1 on Saturday 15th April