Actress Sheridan Smith has revealed that being cast in the title role of ITV1’s new drama series Mrs Biggs was a step up from the roles she usually plays.

The 31-year-old appears in the drama as Charmian Biggs, wife of Great Train Robber Ronnie, with the story told from her point of view.

And she admitted, “It’s really grown-up for me. I don’t usually get to play sophisticated women, I usually play the scruffs, the chavs and the slappers.

“Although I’ve loved the roles I’ve played, it’s been so nice they’ve given me this opportunity,” she added, “and it’s scary, you feel a bit out your comfort zone, but I’m loving every minute.”

Sheridan added that Charmian – who ultimately persuaded her husband to turn his back on a life of crime – was an “incredible woman”.

“She remembers so much, even down to what she was wearing when certain things happened,” she said. “She’ll say, ‘I didn’t have flats then, I had heels’ for example.”

And while she described Ronnie as a “loveable rogue”, Sheridan was quick to point out that the series does not glamourise his criminal past.

“It just tells the female side of the story,” she said, “and I think it is so important to know what she went through.”