Broadcaster Vanessa Feltz and TV presenter Rachel Riley have both admitted to feeling nervous about competing on Strictly Come Dancing this weekend.

The pair are among the 15 celebrities taking part in the BBC One dance-themed reality show.

Despite being the bookmakers’ early favourite to win the eleventh series, Countdown co-presenter Ms Riley said she is struggling to learn the waltz for her first performance.

“I thought it would be good because it’s really smooth and looks effortless,” she said. “But it only looks effortless when they’re doing it right.

“There are so many things to worry about. I’m not used to doing anything with any grace or elegance”.

The 27-year-old presenter blamed her “ridiculously rubbish brain” for her “two left feet”.

She said: “As soon as I start thinking about anything the rest of it goes. I’ve never danced any steps in my life, so trying to think of so many things at once is really out of my comfort zone.

“This key is to stop thinking. You turn the brain off and it will all be alright – possibly.”

Ms Feltz, 51, feared that her “age, weight, lack of talent” would hinder her chances. But the soon-to-be-grandmother added that she has “no lack of desire” to succeed in the competition.

She added: “My professional confidence will be no use at all in Strictly. I’m confident about talking, arguing, broadcasting – but anything athletic, rhythmic... Oh my gosh, no!”

Claudia Winkleman will co-host the accompanying results show for the series, after six couples perform on Friday night and the remaining nine couples perform on Saturday night.