The characters have previously appeared in four episodes: ‘A Good Man Goes to War’, ‘The Snowmen’, ‘The Crimson Horror’  and ‘The Name of the Doctor’.

McIntosh, who plays Madame Vastra, told Flicks In The City: “[Steven] Moffat’s already said that we’re definitely going to be in this next series.”

She added: “It will be sad not to be working with Matt [Smith] again but I’m really looking forward to Peter [Capaldi] taking over and seeing what he does with it. We’ll be helping the Doctor more, but I can’t say anything else. I’d love to work with Daleks!”

The Scottish actress also discussed what she’d like to see in a spin-off featuring the characters: “The sexual themes in Doctor Who should be talked about more and embraced more. It could be edgier and more dangerous. We can do so much in Victorian times, it’s got that steampunk edge to it. Think how freaky that era was with the Elephant Man and all that and just add us into the mix, with time travel and all sorts of weird, wonderful stuff.”

On the possibility of a spin-off, writer Mark Gatiss commented earlier this year: “A lot of people would like to see it – but I’m not sure if anyone has the time to do it.”

Sightseers director Ben Wheatley is rumoured to be helming an episode in Series 8.

> Find out all the latest info on Series 8 in our episode guide.

Are you looking forward to the return of Madame Vastra, Jenny and Strax? Let us know below…

> Order the 50th anniversary special on DVD on Amazon.

> Order the 50th anniversary special on Blu-ray on Amazon.

Watch the Series 7 Part 2 trailer…