BLOOD Brothers has become a stalwart of live theatre - it is one of the world’s longest-running, most beloved musicals - but it started life as a humble play performed at a Liverpool school back in 1981.

Willy Russell’s epic tale of class divide went on to open at the Liverpool Playhouse in 1983 and has since triumphed across the globe, with sell-out seasons in America, Australia, Canada, New Zealand and Japan, scooping up Best Musical awards in London and seven Tony nominations on Broadway.

Blood Brothers is the powerful story of twin boys separated at birth, who grow up in very different households.

While Eddie enjoys middle-class comfort and privilege, with a private education and the promise of a bright future, Mickey lives with his single mother and siblings in a cramped terrace and can only dream of a ‘bike with both wheels’. When the brothers meet by chance, their fate is sealed.

The show features a haunting score, including the showstopper Tell Me It's Not True.

Bill Kenwright’s award-winning production of Blood Brothers - only one of three musicals to surpass 10,000 performances in London’s West End - returns to the Alhambra theatre in Bradford this autumn, starring Niki Colwell Evans as Mrs Johnstone and and Sean Jones as Mickey.

Niki got her break in 2007 when she reached the semi-final of The X Factor, mentored by Louis Walsh. After her debut single Love Me No More in 2008, she made her theatre debut playing Mrs Johnstone in Blood Brothers, to rave reviews.

It’s a role that was first played by Barbara Dickson and has since been taken on by the likes of Carole King, Petula Clark, Mel C and Bradford’s Kiki Dee.

Niki has since gone on to appear in several musicals, including Kinky Boots and Legally Blonde, and as a singer she has toured with pop acts such as Sonia and Lonnie Gordon.

The first time Niki played Mrs Johnstone was in 2012. “I’d never done a musical before. I’d never been part of the theatre world so when Bill Kenwright called me I think I turned it down four times. I was like ‘No, you’re okay!’ but he persuaded me to audition, and my audition was terrible,” recalls Niki.

“But he saw something in me and within a week I was on stage in the Phoenix Theatre. It was such a whirlwind. Since then, I’ve done lots of other roles, mainly funny ones, so to come back to such a dramatic role is very scary but it’s like a dream come true.”

What makes Mrs Johnstone - a working-class Liverpool mother who makes the fateful decision to give away one of her babies - such an iconic musical theatre role?

“It’s because of her strength and the emotions you have to go through when you’re on stage,” says Niki. “She starts as a girl in her 20s, then within 20 minutes she’s got seven kids and has to give one away. It’s a big part for a woman, which is rare at my age. My window is tiny to get a part where you’re on for more than 10 minutes.

“She’s a strong female lead and she’s so real. Every mother must see something in Mrs Johnstone that they’ve also gone through. I know I can. I’ve got two sons, so her Micky and Eddie are my Morgan and Jonah. My kids have had troubles, I’ve had troubles, and the way I look at it is: I don’t have to play her, I just have to be her.”

Bradford Telegraph and Argus: Niki as Mrs Johnstone with Sean Jones as Mickey Niki as Mrs Johnstone with Sean Jones as Mickey (Image: Jack Merriman)

Are you discovering new things about her and the show this time round? “Yes, she’s not such a feisty tiger as I thought when I first did the show. They used to call me ‘Feisty Tiger Mrs Johnstone’,” laughs Niki.

“I come from a family of four, we grew up on a council estate, we had no money, I used to go to school in jelly shoes even in November, and my mum was a tough cookie. You didn’t mess with her and that’s how I thought Mrs J was, or at least that she was how I was, like ‘Don’t mess with my kids or I’ll come at you with a baseball bat’.

“But now I’m older I’ve mellowed. I’m 50 now and I’m not so bouncy as I was 10 years ago, so my take on her is much more grounded. She’s stronger without being quite so feisty.”

Blood Brothers is an emotional experience for the audience, and the cast too. How is it for you as a performer?

“There are a couple of parts in the show where it rips me to shreds,” says Niki. “I do it as though someone is about to take one of my children and I can’t hold back. I have to feel it every time I do it.”

From a young age, singing was Niki’s passion: “It’s like breathing to me, it’s so natural, but actual performing scares the pants off me. I was always happy as a backing singer or in the studio where nobody’s looking at me. When I’m out there I have to forget there are people watching because it’s terrifying.”

How did X Factor change your life? “Completely. It’s given me a career I didn’t think I was capable of, although it did eventually break up my marriage because I was never there. My life since X Factor couldn’t be more different.

“My kids didn’t even know I sang because I’d given it up. So much has happened in the past 15 years career-wise and I’ve got a partner and I’m getting married soon, which is very exciting.”

Apart from Mrs Johnstone, what other musical roles have you enjoyed? “I’ve loved every character I’ve played but if I had to pick one it would be Paulette in Legally Blonde. To go from playing Mrs Johnstone to Paulette in just two weeks was brilliant because it was such a contrast. I’ve never laughed and smiled so much as I have doing the ‘bend and snap’.

“It was the first time I realised I could make people laugh as well as cry.”

* Blood Brothers is at the Alhambra from October 31 to November 3. Call (01274) 432000 or visit bradford-theatres.co.uk