AT 51, Sean Jones is still “running around in a baggy green jumper and short trousers” playing Liverpool lad Mickey in Willy Russell’s heartbreaking musical Blood Brothers into a 23rd year.

“It would definitely be me, Yul Brynner and Topol in the top three,” says the Welsh actor, in recognition of their long service to Blood Brothers, The King And I and Fiddler On The Roof respectively, although Sean has not kept a record of the exact number of performances he has chalked up.

Next week, on his return to impresario Bill Kenwright and Bob Tomson’s touring production for a run from January to late-October, Sean will be taking his Mickey back to the Grand Opera House in York.

Musicals were not his first love, but maybe this was destiny. “I’d had had a string of auditions for musicals off my agent but was getting very disconcerted as I’d trained to be an actor, not a singer and dancer, and then he said again, ‘I’ve got you an auditionfor a musical.”

However, this time it was different. “It was the chance to be cover for Mickey in Blood Brothers, which has always been my dream role.

“It’s the most prepared I’ve ever been for an audition! Thankfully I got the gig as understudy on tour, and I remember we came to York on that first tour in 1999.”

He had trodden the boards in York previously. “On my first time there, I did [Agatha Christie’s] A Murder Is Announced with Richard Todd in 1993 in my first job after drama college, with Bill Kenwright as producer, and I remember thinking, ‘that might give me an inroad to Blood Brothers’!”

Sean would subsequently become embedded in Russell’s musical, even meeting his wife, actress Tracy Spencer, though the show. “Tracy played Mrs Lyons. We got married in 2004 on a two-show day when we were at the Cardiff New Theatre,” he says.

“We got married in the morning, did the matinee, took the cast out for a drink, then did the evening performance.

“Blood Brothers is absolutely ingrained in me. When Tracy fell pregnant with Eleanor, after three months, we decided we would go out on tour for four years in the show!”

In Russell’s fateful musical, when deserted mother of seven and housekeeper Mrs Johnstone discovers herself to be pregnant with twins, in a moment of desperation, she enters a secret pact with her employer, leading to Mickey and Eddie being separated at birth, growing up on the opposite sides of the tracks, only to meet again with tragic consequences.

“It’s such a journey that Mickey goes on and such a great role for an actor to get his teeth into, with all the high comedy that Willy Russell has written that requires plenty of skill, and then the final hour that takes the audience to some really dark places, with the last few scenes being so harrowing.”

Out of the past 22 years, only eight have not been spent by Sean stretching that trademark baggy jumper over his knees. “It’s one of those things, whatever job anyone has, there’s a certain amount of repetition, whether working in a bank or a shop. With Blood Brothers, same job, same lines, but the audience keeps you fresh,” he says.

“On top of that, Mickey is such a phenomenal role that I’m still finding new things in it after all these years.”

Playing Mickey for more than two decades, Sean has found his performance evolving over that time. “When you’re using techniques in order to get yourself into the zone for those last 30 minutes, the more you c.an draw on your own emotional memories, because all you are as an older person is a young person with more despair.”

Sean left the show for three years after his parents became poorly. “I needed to be there, with them,” he says. “But I always felt there might be a chance to come back.”

When Bill Kenwright asked him to reprise his Mickey once more, he said yes. “It’s like, go find me a better musical theatre role than Mickey,” says Sean. “There’s a plethora of great roles in musical theatre but none that goes on the journey that Mickey does. It’s brilliant storytelling theatre with so much comedy and then absolute heartbreak.”

The tour publicity states this will be Sean’s “final ever tour of the show”, but will it? “I’m happy to carry on doing it as long as Bill Kenwright is happy for me to get away with doing it!” he says.

“I appear to still have the same energy, hitting all the right notes in the right order, and as long as that keeps happening, I’m happy to keep going, but all I want to do is to keep on being a jobbing actor. That term shouldn’t be a slur. It’s about doing a job I love, whether in Blood Brothers, or in a small play at Theatre Clwyd, though I’d also love to do more screen work.”

Blood Brothers runs at Grand Opera House, York, from April 5 to 9, 7.30pm plus 2.30pm, Wednesday, Thursday and Saturday. Box office: 0844 871 7615 or at atgtickets.com/York.

By Charles Hutchinson