JOHN Michie's feet have been battered into submission over the years, having schlepped the streets of Glasgow as a Taggart cop and more recently the bumpy cobblestones of Coronation Street.

Now, however, the actor's soles and toes are set to suffer real torture as he joins the STV Appeal Dance Marathon 2013 to raise money for children affected by poverty in Scotland.

It's not quite like a scene from a 1969 movie classic – but John admits it's close.

"At one point it was going to be a They Shoot Horses Don't They 24-hour marathon, but I'm glad it's only 12," he says.

"And unlike the characters in the movie we get little breaks, and it's good fun.

"It's one of the things actors can and should do. And I have to remember STV had been very good to me for 11 years. And I love going back to Glasgow."

He adds, smiling: "I've run the real marathon four times now, but this is almost as hard."

Was Michie, 56, who grew up in Edinburgh, a dancer in his younger years?

"I wouldn't call myself a dancer, and neither would my wife who is a dancer," he says of Carol, mum to their three kids.

"She thinks anyone who can dance with me must be a genius. She will help me at home with a few steps, but otherwise we only dance at family dos. I won't ever be doing Strictly Come Dancing."

Not even if the producers waved a cheque for £150k in his face. "Well..." he says, grinning, a note of hesitation in his voice. "Never say never."

John sounds incredibly cheery for a man who's about to meet his end ... in a television sense, that is.

He's become a massive hit with Coronation Street fans playing killer Karl. But he has to go because the fundamental rule of soap TV is no crime goes unpunished.

John said: "I've had a fantastic two years. And it's been great being nasty, and nice to be on the other side of the law.

"I was laughing the other day filming the final scene when the cops are reading me my rights, and I was enjoying hearing them struggle over getting the rights right."

John was entirely convincing as Karl.

He said: "My dad is from near Glasgow but mum is from Rochdale, which is just up the road. So that helped with the accent, and I did have some voice coaching along the way.

"Arriving here makes you realise it's a great big rumbling beast that you jump on it's back for a while then you fall off.

"It's so different from a show like Taggart which was just so contained, and smaller.

"With Taggart you had longer to rehearse, and longer to shoot. But with Coronation Street it's so fast. When you have a big storyline it can be stressful, but at other times you have so little to do.

"I've also learned a lot, how to make decisions quickly, to decide how you're going to play a scene, and go out and do it.

"What was also good was I've known Michelle Collins for a long time.

"But they are an incredibly friendly bunch of people here. And there's a nice equality about the whole thing. I found it all brand new."

HE'S had to come to terms with the profile of Corrie. "I thought Taggart brought attention but nothing like Corrie. It's a lot to deal with.

"You don't appreciate how important your privacy is until you lose it. You try and find ways of disguising yourself but you can't fool everybody. And sometimes resisting the interest takes even more energy."

He smiles at the notion that acting can take you in any direction. "I'm going to be a surgeon next," he says of his upcoming Holby City stint. "From scally to surgeon in one leap. It's a crazy world. But I'm glad I'm not going to be another cop straight away. That would be a bit too much."

He's had a great range of characters over the years. But what can we expect from his Holby character?

Is his character a heartthrob?

"I'm a wee bit old to play a heartthrob," he says, grinning.

Not at all John. Look at Corrie. You had Stella and Sunita eating out of your hand.

"Well, that's true," he laughs. "My wife is bemused by the fact I still get cast in these parts.

"But I've got an outline of my Holby character, and he'll be more easy-going sort, but with issues in his past. You've got to have issues in drama.

"I've been watching documentaries about brain surgeons to get an idea of what they are like. I've got a couple of books to read up on them and a week in Spain between the two jobs so I'll be studying.

"But it's an exciting challenge and great to go from one job to the next. And I'll be filming in London, so I'll be back home."

But first he has to dance his way to charity success, alongside Coronation Street co-star Catherine Tyldesley, who plays Eva Price.

"Yes, I will have sore feet," says John, "but it's all for a fantastic cause with every penny raised going directly towards helping Scotland's children, and I'm really delighted to be involved."

l This year's Dance Marathon will take place in three cities, with Glasgow's day-long stint at the Hilton Hotel on August 25.