Karen Gillan has said she and Matt Smith breathed a “big sigh of relief” after the first episode of the new series of Doctor Who finally hit the small screen.

The stars made their debut as the new Time Lord and his assistant on the BBC One sci-fi show on Saturday.

Karen, 22, told This Morning: “We were filming for nine months and you get into this bubble almost and you sort of forget that it’s actually going out on television, and it did on Saturday and we’re all breathing big sighs of relief because it seems to have gone down quite well.”

She added: “The anticipation was quite pressurising, but mostly just exciting because people care so much about it. It’s a real privilege.”

Karen, who appeared in a minor role in Doctor Who three years ago, defended her character, which has been criticised for being too sexy.

She said of Amy Pond: “She wears lots of short skirts… It’s interesting, it’s part of the plot and it’s not that bad.”

Karen also revealed that before her casting became public, she decided against telling her mum that she had landed the coveted role.

She said: “To keep it from my mum, who is one of the biggest Doctor Who fans, for two weeks was tough.

“I was allowed to tell her but decided against it, because I think she would’ve burst. She would’ve told somebody, she even has the Dalek bubble bath!

“But I just remember her face when I told her I got it… it was a picture, it was a amazing.”