HERS is one of the best known rags-to-riches stories of recent times. A single mother in 2001 living on a modest income, she shot to fame as a member of Hear'Say, thanks to reality show Popstars.

When their first release Pure And Simple became the fastest-selling debut single by a group, it looked like her place was assured in the ranks of pop royalty. Alas things quickly fell apart, and amid flop follow-up singles and squabbling within the band, Kym Marsh decided to go solo.

Her own career fared little better and followin

g her third release, she was dropped by her record company. During this time she had also reportedly split from her husband, ex-EastEnder Jack Ryder.

Although the couple have long since reconciled, life has been tough for Marsh, with both she and Ryder seemingly finding it hard to secure permanent work - he signed on with Family Affairs just as the soap was axed. So has it been a case of from rags to riches and back again?

Now hoping to carve out a new career as an actress, Marsh has followed up a guest appearance in Doctors last year with a one-off role in Holby City on BBC One on Tuesday.

The 29-year-old seems genuinely excited about her change of profession, and although it is made clear before the interview that she will only answer questions relating directly to her role, she seems happy to talk quite candidly about where life is taking her next.

"The character I play in the show is called Myrna," she explains. "She's 22, 20 years younger than her boyfriend Gerry, who's a doorman. To be honest, she's a bit of a rough old bird. She's got a sharp tongue on her and very protective of Gerry.

"But she's fun and she certainly has her comedy moments. I loved playing her." Warming to her theme, she reveals a little of the episode's storyline.

"Gerry goes into hospital," she says. "He's been stuck in a lift for three days and he's dehydrated. He's got a lot of stomach pains and he's not feeling very well. No-one knows what's wrong with him until the end of the programme when we all find out."

Marsh's storyline is less than serious. "Oh yeah, it's quite light-hearted," she says. "I think I prefer that and I'm glad I wasn't the patient. Everyone tells me that after a while you really start to feel ill.

"We did three days on set. It was good fun and nice to see how everything works. But there was no messing about. You've got to knuckle down and get on with it. It's all right having a laugh and a joke and stuff like that, but when it comes to doing the work you've got to be 100 per cent on it."

Despite that, she gushes: "I really enjoyed it. It was a pleasure to be involved, everyone was very nice and very welcoming and it was a good experience for me.

"It's the second thing I've done now for TV and it was very different to the first, which was Doctors. I appeared in that last year.

"I auditioned for the part. I was really nervous. But I've learned now that you've just got to go in there and do your job. Go for it and don't let nerves get in the way.

"That said, it's one thing to perform your lines at home and another to do it in front of a little camera and a few people who are influential. I don't think the nerves will ever go away, but it's a matter of trying to keep them under control.

"Initially I thought my background was going to be a bit of a problem. I hate the fact that sometimes people get pigeonholed, with folk saying: 'You're a singer so you can't do that'. So I fully expected it would be that case for me. But, I haven't found that, people have been really welcoming."

• Holby City, BBC One, Tuesday, 9pm