Former 'Doctor Who' star Pearl Mackie wants the next Doctor to be "non-binary".

Peter Capaldi and Pearl Mackie

Peter Capaldi and Pearl Mackie

The 34-year-old actress portrayed Bill Potts - the first openly gay companion to travel with the Time Lord - opposite Peter Capaldi's Twelfth Doctor, starring in 13 episodes.

Pearl - who came out as bisexual last year - thinks that now the sci-fi show has had its first female Doctor, following Jodie Whittaker's casting, it is time for the time traveller to be a genderless alien.

In an interview with The Daily Telegraph newspaper, she said: "I think it would be great to have someone non-binary playing the part.

“The Doctor doesn’t really identify with human constraints at all. So I feel that could be a logical next step, wouldn’t it?”

Pearl is proud to that her alter ego Bill was able to help viewers embrace their own sexuality and give them the courage to come out.

She said: "That’s not something you ever imagine when you decide to be an actor: that you are going to help shape someone’s life, or their journey, particularly something as complicated as nuanced as coming out.”

Although Pearl was the first openly gay companion, Captain Jack Harkness - played by John Barrowman - revealed he was bisexual when he met Christopher Eccleston's Ninth doctor, making the character the first to openly identify as anything as heterosexual in the BBC One programme.

Pearl will next be seen in ITV crime drama 'The Long Call', which will star Ben Aldridge as Detective Inspector Mathew Venn, who is openly gay, and she thinks it's 'phenomenal" that a homosexual character will lead a primetime programme.

She said: "As a member of the [LGBT] community myself, it’s so important that we see these stories that don’t just focus on sexuality and relationships, but the rest of a character’s life.”

Adapted from the best-selling novel of the same name by Ann Cleeves, 'The Long Call' follows the story of a Detective Inspector Mathew Venn and his husband that return back home to a religious West Country community that shunned them when they were 18.

Pearl plays plays Venn's deputy Jen, who is a single mother and a domestic abuse survivor.