THERE are some who have pre-conceived ideas about what to expect from Alan Ayckbourn. For many, the prolific writer and director of almost 80 plays is the high priest of English middle class mores, his work awash with disaffected suburbanites falling apart in immaculately constructed, if increasingly absurdist, fashion.

Confounding expectations, the 78-year-old Ayckbourn's latest work is a six hour flight into dystopian speculative fiction told in two parts. The Divide is a major component of Edinburgh International Festival's 70th anniversary theatre programme.

Set a hundred years from now, Ayckbourn imagines a world decimated by a deadly virus that makes any contact between men and women fatal for both. In a country divided by gender, men wear white for their purity, while women dress in black as a mark of their sins. Given the state of the real world right now, the scenario looks worryingly relevant and The Divide arrives alongside what looks like a revival of dystopian drama onstage and screen like the television adaptation of Margaret Atwood's novel, The Handmaid's Tale. With future-shockers such as Humans and Orphan Black also on the go, Ayckbourn seems to have hit on a troubled zeitgeist.

“The best sci-fi, in my opinion, usually takes the form of a cautionary tale for the present,” he says. “If we continue to do this, then this will happen. I see The Divide as a sexual satire in which the enforced separation of the sexes, at the risk of human extinction, causes an upending of social norms when heterosexuality is considered unnatural and same sex relationships are the established norm. Yes, it is dark, but it’s equally quite funny, too.”

As is often the case with Ayckbourn's work, The Divide has a deceptive classical root.

“It initially took the form of two diaries,” he says, “a brother and his sister’s chronicling their childhoods being raised in a strictly orthodox household by their two female parents, their Mama and their Mapa. As I wrote it, all sorts of things then got added, minutes of the local village council meetings, official inter-departmental memos, newspaper correspondence and editorials, etc. It ended up as a re-telling of the Romeo and Juliet story.”

One of the things that has distinguished Ayckbourn during his long career, especially during his thirty seven year reign as artistic director at the Stephen Joseph Theatre in Scarborough between 1972 and 2009, is a predilection for directing his own work. The Divide, however, sees him take a very deliberate step back from overseeing that part of the dramatic process in a liberatingly playful manner.

“Traditionally, I have directed the first productions of all my plays,” he says. “Lately, this has become something of what one might describe as a symbiotic process, and I recently became conscious that for the author, having the director sitting on his shoulder during the initial writing process could be detrimental to the writer’s freedom. Which, added to all the other restrictions – the financial and physical limitations of the Stephen Joseph Theatre space – was becoming a trifle stifling. I decided the writer was to be allowed complete freedom without limitations of space or budget. In other words to write something that the director in me would find un-directable! The result was a piece on a very large scale, requiring dozens of performers and numerous locations and covering a considerable time scale.”

The Divide is produced by the Old Vic, the London based theatrical institution which between 1963 and 1976 housed the early incarnation of the newly established National Theatre, then run by Laurence Olivier. In an earlier incarnation, the Old Vic company was one of the main draws at the very first Edinburgh International Festival in 1947, and this new production by Old Vic associate director Annabel Bolton looks set to be quite a reunion. Given his usual position at this part of the process, is Ayckbourn not a tad curious about how such an epic undertaking as The Divide is getting on without him?

“I imagine all sorts of things will come out of rehearsals,” he says, “but I will take no part in those, leaving that to Annabel Bolton and the Old Vic team. I’m busy directing another, far more manageable one, back here in Scarborough.”

Even so, having to keep his distance, however much by choice, remains “Very weird for this director, I have to say. Whereas this writer is very excited and can’t wait to see what they make of it.”

The Divide isn't the first time Ayckbourn has used sci-fi as a backdrop for his work. One of the best examples of this is his 1987 play, Henceforward..., in which a composer estranged from his family co-opts an android to play the part of the perfect domestic hostess in a bleakly comedic future-scape. As with many of Ayckbourn's generation, he was a fan of the genre from an early age.

“I used to read a lot when I was young,” he says, “and it’s seeped into my work, as you say, with plays like Henceforward… and Comic Potential. And in a great deal of my children’s work, too, Miss Yesterday, Invisible Friends, Callisto 7, The Jollies and My Sister Sadie to name but a few. In order to write for the younger generation, you create a universe that you are both able to share on an equal footing. I’m not the first adult writer to discover that.”

While The Divide looks to the future, in terms of his work beyond it, Ayckbourn has one foot very much in his own past.

“I’m currently directing a revival of my 1979 play, Taking Steps, for Scarborough,” he says, “and, straight after that at the same address, my new one, A Brief History of Women, which is set in the recent past. Later in the year, I’m scheduled to direct a revival of the 90’s musical which Andrew Lloyd Webber and I wrote, By Jeeves. It’s a sort of busy year for me.”

In the meantime, with a new wave of speculative fiction moving into every artistic form, The Divide is very much of the moment. While Ayckbourn points out that in sci-fi, “a possible future is a great way to make a point about the present", his aim with the play is not to change worlds, but is “primarily to entertain. Then to re-examine inbuilt prejudices and perhaps, hopefully, to start a few arguments, as well.”

The Divide, King's Theatre, Edinburgh. Part 1, August 8, 16, 18, 7.30pm, August 11-13, 15, 17, 19, 20, 2pm; Part 2, August 9, 11-13, 15, 17, 19, 20, 7.30pm, August 16, 18, 2pm.

www.eif.co.uk