Richard Attenborough’s 1969 film of Oh! What A Lovely War tends to overshadow the piece’s theatrical roots. Amazingly ahead of its time, it had been put together by Joan Littlewood and her ensemble Theatre Workshop at the Theatre Royal, Stratford East in London six years earlier.

It was and remains, a deeply polemical work, satirising the First World War and, to a certain extent, all war.

Interestingly, Littlewood was wary of permitting many re-stagings — and when she did, always insisted that the original format should not be played around with, that of a show being put on by a musical troupe of vaudevillians, allied to photographic slides which demonstrated the true horror of life and death in the trenches.

The Northern Stage production, which ends its much-garlanded tour at the Playhouse next week, remains fairly true to the Littlewood approach.

The co-director is Erica Whyman. I asked her if the thrust of the play makes war always bad, merely unjustified or at the least needing to be questioned.

“It needs to be questioned, I’d say. Indeed some modern audiences might be horrified at the reverence with which Joan Littlewood treated the First World War. But it does ask tough questions: there’s an interesting investigation of the concept of patriotism and how decisions should be made on behalf of people who sacrifice their lives, or are about to lay them on the line.

“The play’s particularly angry with the senior officers who made those decisions, and, of course, it’s very much about class — there’s a real sense of rage there. The decisions were made entirely by members of the upper class, while the vast majority of those killed were working men who’d already given quite a lot to their country.”

Whyman believes that the play resounds well today with the war in Afghanistan, as opposed, say, to the Second World War.

“In 1939 it was much more clear cut in that there was a moral reason to fight. The reasons for going to war in Afghanistan are complex and harder to understand — what the objectives are, whether we will come out of it creditably, which is perhaps what it shares most with the First World War.” In these heady political times, I asked Whyman if theatregoers have to be of an anti-war bent, or tremendously ‘left-wing’ to reap full enjoyment from Oh! What A Lovely War?

“Absolutely not: I would really disagree with that. Littlewood came from a very clear socialist background and held very strong views. But I repeat: she didn’t really suggest that all wars are bad — it’s just that terrible things happened in this particular war and, most importantly, that perhaps we might not have learned the lessons from it.”

One thing Erica Whyman specifically enjoys about the show is the opportunity it gives her to direct music and singing rather than pure drama (Playhouse regulars may remember, for example, her 2008 production of the gritty Our Friends In The North).

“It’s a great heartening process, very uplifting, even in a tragic story as some of this is. I enjoy directing a song when I might unleash its emotional story for an actor.

“And let’s not forget the wryness of the humour in the play; some of it is very touching and very particular to England.”

Not only is Whyman co-directing this production with Sam Kenyon; she’s also been the chief executive of Northern Stage for nearly five years, a post she took up after three years as director of the Gate theatre in Notting Hill.

So how does being a business front work alongside being a creative person (she’s also the company’s artistic director)?

“I don’t think of myself as a business person; it’s just that the buck stops with me as its most senior manager. It’s not quite as stark as you might think, though. It’s quite normal in other areas of work; only in the arts are people sceptical about merging the roles.

“There have been some very distinguished examples in our theatrical history of great actor-managers as well as director-managers.”

Yes — think Laurence Olivier, Donald Wolfit or Peter Hall. Erica Whyman is clearly easing herself in to that list.