AFTER 30 years of working together, George Stiles and Anthony Drewe can lay claim to being one of the longest-running double acts in musical theatre.

Yet speaking today, promoting their original score for a new version of Half a Sixpence in Chichester, the pair seem mildly incredulous about this.

“We have bopped along, miraculously, longer than anybody else bar Andrew Lloyd Webber and Sir Tim Rice,” Drewe says.

Perhaps the career highlight in this time was writing the new songs and vocal arrangements for Cameron Mackintosh’s worldwide musical hit Mary Poppins, which debuted in 2004. A far cry from the duo’s early days, when they would decorate houses and paint Subbuteo football players to fund their burgeoning songwriting careers.

Stiles and Drewe have collaborated again with Mackintosh – along with writer and Downton Abbey creator Julian Fellowes – for Half a Sixpence, based on H.G Wells’ novel Kipps: The Story of a Simple Soul and the initial musical adaptation of the book in 1967. Then, pop star Tommy Steele was the undoubted central figure of the performance. Now, the show is much less “star-centric.”

Fellowes has written a whole new script, and Stiles and Drewe have edited the musical’s existing songs whilst adding some original compositions. “There isn’t a bar of music we haven’t interfered with in some way,” says Stiles.

Arthur Kipps is a ‘disguised’ autobiographical portrayal of Wells, based on the writer’s miserable stint working as a draper in Southsea. After inheriting family wealth, Arthur starts to move into lofty social circles with the notion that it will make him happier – to the dismay of his sort-of girlfriend Ann Pornick, who sees that he has forgotten his working-class roots, and himself.

Helen Walsingham is the middle-class woman who falls in love with Arthur. Ultimately he must make a decision about which woman he chooses, and which life he chooses.

Drewe says, “He thinks money will be his passport to a different social class, but as soon as he starts living in that society he realises he doesn’t belong. At the time of the novel, money implied power. It is more the power structure than the class structure that is prevalent.”

And, to the composer, the musical has very modern resonances. “Look at recent times: it has been so depressing to read the papers and see the latest scams politicians are trying to pull off. That corruption of people in power is also visible in the production.”

Stiles suggests that rather than wanting to distinguish between classes, Wells was “writing about the difficulty we have in Britain of letting people rise up through the structures that are in place. We are all very good at cheering somebody on until they become famous – ‘well done you’ – and then as soon as they have a problem, we’re mocking them.”

Chichester is home to a university with a flourishing musical theatre course. If this might be viewed as small evidence of young people engaging with the medium of the musical, Stiles and Drewe think that the exposure of small children to singalong blockbuster films like Frozen leaves “boys and girls wanting to grow up and recite songs like that.”

From similar early aspirations, The duo’s lives were changed by winning an Olivier Award (for Best New Musical) in 2000, for their production HONK! 16 years on from that breakthrough, their passion for their art is still strikingly evident.

“You can encapsulate a feeling in a minute-and-a-half song as well as you can in two or three whole scenes,” says Drewe. “That’s what is so exciting about it.”

Half a Sixpence, Chichester Festival Theatre, Oaklands Park, runs from now until September 3, from £10, tickets at www.cft.org.uk/whats-on/event/half-a-sixpence or call 01243 781312