Cher has revealed how nervous she was on her first day on the set of the Mamma Mia sequel.

The singing star joins the cast for the highly-anticipated follow-up to the 2008 box office juggernaut, playing the mother of Meryl Streep’s character.

She told a press conference: “I was terrified because everyone had been together and my character wasn’t very liked, so I was nervous, but everyone was nice to me.

“Meryl was behind a piece of scenery watching me do my number and that made me feel good after the fact.

“It was hard to go on a set where you were a stranger to everyone.

“I knew some of the people, but to have such a ‘mean grandmother’ thing and then work your way into the story and be friends with everybody… but I felt really kind of loved and kind of a great grandmother.”

The singer said she had been a long-time fan of the music of Abba, which underpins both the original movie musical and its sequel Mamma Mia: Here We Go Again.

She added: “In America we knew the hit songs, but then when I heard Fernando I heard a different thing. I heard the acting of it and I didn’t realise the songs were so complicated and I didn’t realise how orchestrated and produced they were.”

The sequel sees the return of original cast members Streep, Amanda Seyfried, Julie Walters, Pierce Brosnan, Christine Baranski and Colin Firth, as well as the addition of Lily James as the younger incarnation of Streep’s Donna Sheridan.

James said: “Donna Sheridan is the most unbelievably brilliant, extraordinary woman and Meryl Streep is also all those things and her Donna was everything, and I just tried to watch it and capture what Meryl did, of that fearless uninhibited woman.

“I watched the (original) film over and over again to get into her physicality, of how open she is to the world, to hope that my Donna could grow into that woman.”

Mamma Mia: Here We Go Again is released in UK cinemas on July 20.