When I first saw Blood Brothers – nearly twenty years ago now – I loved everything about it. And as this current production shows, the storyline, acting and music still have the power to move me.  On a deprived Liverpudlian council estate, single mother Mrs Johnstone is trying to scrape together an existence for herself and her seven children; living from hand to mouth and unable even to pay the milk bill, she is persuaded – or pressured – into giving away one of her new-born twins. The recipient is the middle-class Mrs Lyons, and as though they’ve struck a deal with the Devil, the decision returns to haunt the women as the two boys grow to adulthood.

It's not at all easy for an adult to portray a child on stage – but Josh Capper is highly convincing as the seven-year-old Mickey, playing at Cowboys and Indians and galloping around the stage on an imaginary horse. Capper’s portrayal is equally realistic when Mickey is older, and severely down on his luck. There’s a fine chemistry too between him and Alison Crawford, playing Linda – the girl who’s loved Mickey since the day they began school. Crawford is hilariously strong as the courageous youngster in bunches, and grows beautifully into a slightly brazen teenager, determined to let her chosen man know just how she feels about him.

But the top accolade has to go to Lyn Paul, astonishingly reprising a role she first played in 1997. Turning in a faultless, moving performance as the birth mother, she is totally and completely believable from start to finish. It’s a heart-felt and emotional tour de force, which left her looking wrung-out by the final curtain, and I could almost literally feel her character’s pain as she watched the heart-rending outcome of her decision.

Narrator Dean Chisnall is an omniscient, slightly menacing presence, making it clear from the beginning that there is a tragic inevitability about the consequences of separating the boys. He pecks away continuously at the two women, giving them no respite, as if their very consciences are speaking out loud. Despite this foreshadowing, the ending is still a shock; the closing scene cleverly reflects the opening one, taking the audience and the story full circle – and musically, the final number leaves every nerve tingling too. You would have to be made of very stern stuff not to be moved by it all.

The score has stood the test of time, remaining catchy and pertinent, with clever use of repeated refrains.  The minimalistic set is cleverly used too, evoking both town and country, and the slick handling of props was like watching a magician at work; at times you really couldn't see how certain things disappeared and reappeared.

Unfortunately though, there’s one fundamental issue which slowly but surely intruded on my enjoyment of the spectacle.  Although Capper and Hutchinson (playing Eddie) acted well together, and harmonised like angels, they simply aren’t believable as twin brothers: they’re too far apart both in looks and apparent age.  It’s a strange piece of casting which I did my best to ignore, yet after a while I found I just couldn't suspend my disbelief any longer.

However, the strength of both the songs and the cast were enough to carry me along with the storyline. And – while it’s true that Willy Russell's Blood Brothers has been around for decades – its content and messages are as relevant today as they were in the 80’s.  The poignancy is timeless.