It is almost inconceivable that – 27 years after first appearing on the London stage – Willy Russell’s Blood Brothers, a simple but epic story of twins parted at birth, would still be packing them in at the Phoenix Theatre in London, and regularly up and down the country on tour.

That initial production in 1983, starring Barbara Dickson in the pivotal role of Mrs Johnstone, had only limited success, and it was not until Bill Kenwright took the helm, re-worked and re-launched it in 1986 that it became the enduring classic which we see today.

Niki Evans (who stole the nation’s heart in 2007 with her performance on TVs The X Factor) is the latest in a long line of Mrs Johnstones, and is a revelation. Her power-house performance literally fills the auditorium, and I cannot remember ever being as moved as I am by the all-too real heart-break in her voice when delivering that final song, “Tell Me It’s Not True”.

Paul Davies (Eddie) and Kelly-Anne Gower (Linda) are also excellent, and Sean Jones is outstanding as Mickey. The real star however is Russell’s razor-sharp prose (as in the summer sequence) and heart-wrenching songs (“Easy Terms”, “Bright New Day” and “Marilyn Monroe”).

They combine without seeming effort to move along the story of the two brothers, brought up at opposite ends of the social spectrum with their whole lives pre-determined by their status in society, and drawing to an inevitable, tragic conclusion.