It’s been revealed today that when former Gavin & Stacey actress Sheridan Smith auditioned for the role of Charmian Biggs – for the forthcoming ITV drama, Mrs Biggs – she was so moved by the plight of the Great Train Robber Ronnie Bigg’s wife, that she wept openly as she read for the part.

Sheridan was of course just a child as the real life Charmian was facing heartbreak and the breakdown of her family’s lives after Ronnie escaped from prison and fled to Australia and then Brazil, where he eventually remarried and had a son in order to evade extradition.

The Daily Mirror reports, “At her audition for Mrs Biggs, Sheridan was the last to try out for the role.

“She was asked to portray Charmian’s grief at the loss of her 10-year-old son Nicholas, who was killed in a car crash after the Biggs had gone on the run in Australia.”

Apparently, Sheridan’s powerful performance left the producers “speechless”, and of being able to parlay such on-screen emotion, Sheridan said, “You have to draw on personal things to get that kind of emotion…

“I lost my eldest brother, so my mum went through that.

“Because I don’t have children, I tried to use that when I was playing those scenes.

“It was really traumatic because I felt for Charmian so much. No mother should lose a child.”

Sheridan, who met the real Charmian on the set of the drama, added, “Charmian went through all these emotions, so you don’t want to fake it.

“You have to go there, to that dark place, and get it out. That particular scene we’d get the cameras rolling and then I basically had a breakdown.

“That day was the hardest. I remember bawling my eyes out before I even auditioned. It’s such a moving story.

“I’m a hopeless romantic and at the heart of Mrs Biggs is a love story.

“I’ve never read something that I’ve wanted so much to play. I was still in tears after the big emotional scene in which she has to bury her son and it was all quiet in the room.

“I just went back to my car thinking, ‘I was rubbish, I was rubbish’. I was terrified and really didn’t think I’d get it.

“I thought ‘a role like this, they’ll be seeing so many brilliant actresses and I don’t stand a chance.’”

But of course, that wasn’t the case and the show’s producers immediately hired Sheridan for the five part drama, which airs next month.

Here’s a clip of both Sheridan and Charmian discussing the drama…