Tom Conti: my big break was all thanks to the cost of a train fare to Glasgow

But then he has developed his talent wonderfully during an auspicious acting career.

"What are you trying to do, depress me?" he says in mock serious voice, before breaking into a smile.

The comment comes on the back of hitting the Paisley-born star with a few numbers. Tom has now been performing on stage for an incredible 56 years.

He's now 73, and set to return to Glasgow in epic courtroom drama 12 Angry Men. He clearly doesn't need the money, so he must quite enjoy it?

"I suppose I do," he says, laughing. "It's a real fun play to do. And the audience is caught up in it from beginning to end."

12 Angry Men was a 1957 courtroom drama starring Henry Fonda, which first transferred to the theatre in 1964.

Tom argues that recognition factor is bringing people into theatres to see the show rather than negate audience interest.

"People forget what happened in the film," he explains. "They don't remember the arguments, the deliberations. They just remember Henry Fonda, and that it was good."

But courtroom dramas aren't fun, are they?

"Well, there are a lot of laughs in the play. We've worked hard to find them because drama in itself isn't enough, you need the counterpoint."

Tom Conti is in himself a reason to go to theatre these days. Over the years he's continually proved himself to be a class act in stage triumphs such as Whose Life Is It Anyway and Jeffrey Barnard Is Unwell.

But in conversation he always downplays his status. For example, in rewinding on the beginning of his stage career, the self-deprecating actor maintains his early success had nothing to do with talent.

"At the end of my first year in drama school, Dundee Rep was looking for an actor for a play The Vanity Case," he recalls.

"But it just so happened it was the time of the Edinburgh Festival and every single actor in Scotland - except me - was working.

"The director at Dundee Rep said he couldn't afford the train fare to being an actor up from London so they called the drama school and asked if there was anyone who could do the job.

"They said, 'Well, we've got this young lad who seems to remember the lines.' So I got the job - by default. You see, I was just a train fare from Glasgow."

It's more than a talent for remembering lines which has seen Tom Conti star in films such as Shirley Valentine and the delightful Reuben, Reuben.

He's always a strong, charismatic character. Which he is off-stage. In recent months, for example, he's been making headlines with his latest role; Conservative Party Supporter.

Now, you'd assume the son of two hairdressers from Paisley - his dad an Italian immigrant - would preclude any Tory leaning whatsoever?

"Perhaps," he says, with a shrug. "But my whole feeling on the change (he was a Labour supporter) is reflected in a recent TV interview in which a wee working class man from Glasgow was asked, before the election, his thoughts on the outcome.

"This man said simply; 'Labour has outlived its usefulness.'

"And he got it in one. There was a time when Labour protected people like miners but now the party has become redundant. The world has moved on.

"What's also disappointing is the propagation of hatred from Labour. I don't like that at all."

Yet, he's an egalitarian. And there are battles to be won, against bankers, the tax avoiding companies?

"Yes, I am and there are. But Labour didn't fight these battles.

"Tony Blair had such a majority he could have given Westminster Abbey back to the bloody Pope and he'd have gotten away with it.

"He could have sorted the education system, poured money into reducing class sizes, and what did he do? He decided to kill hundreds of people (in Iraq) instead."

Tom considered (briefly) going into politics.

"Yes, I thought of standing as Mayor of London."

He adds, grinning; "I did think about it for five minutes but then people around me said it would ruin their lives."

Was his wife (Scots-born actress Kara Wilson) one of those people?

"Yes, she was," he says, laughing. "And my daughter (Nina, who's a ventriloquist). They realised the magnifying glass would be turned on them.

"And they were right."

If Tom Conti believes science and engineering to be the future rather than arts, where does he stand on acting?

"I'd advise against coming into the business," he says in serious voice. "There are far too many hopefuls. And hope doesn't get you anywhere.

"It's such a tough business. In fact, two of my friends in the business, including Phil McCall, have killed themselves because of the pressure, and many others have become drunks.

"I wouldn't recommend acting. You are always being judged."

Yet, Tom Conti has been judged incredibly well over the years. Is it the love he feels on stage and the great crits which keep him coming back?

"Well, theatre is only two and a half hours work a day, as opposed to fifteen in the movies," he says, grinning.

"But the real truth is I love theatre. I can't not do it.

*12 Angry Men, the Theatre Royal, June 22-27.