IN a rehearsal room somewhere in London, the day is hot and the atmosphere inside is chilling.

Menacing music throbs as armed personnel in gas masks surround a man strapped to a chair. What happens next is not for the squeamish: Ministry of Truth drone Winston Smith, Comrade 6079, has been trapped into an act of rebellion and is sent to the notorious Room 101 for torture.

The play in rehearsal is the new Headlong/Nottingham Playhouse/Almeida Theatre stage adaptation of 1984, George Orwell's story of Big Brother, dictator of the totalitarian state of Oceania, and its satellite state of Airstrip One, formerly known as Great Britain, where Smith lives in London, altering historical records to suit the ruling party's current doctrine.

The Headlong co-production opened last Friday at Glasgow's Citizens Theatre and its tour will visit York Theatre Royal from September 16 to 20, under the direction of its co-creators, Robert Icke and Duncan Macmillan, whose radical staging explores surveillance, identity and why Orwell's vision from 1949 is as relevant now as ever.

Robert first read Orwell's novel in his teenage years.

"So I knew the book when I came to work on the play," he says. "It’s like a Shakespeare; everyone has a print of it in their head, but it’s often nothing to do with what’s actually printed on the page.

"My journey with Duncan [Macmillan, who has adapted the book for the stage] has been very much to work out what the relationship is between the version everybody thinks they know and what’s actually there. If you discover that the actual is more interesting than your imagined version, then you go ahead. If not, then you don’t.”

When he first read the book, it felt a bit like a punch in the face, recalls Robert. "It’s got a visceral impact, which oddly does some disservice to the detail in the book," he says. "Everyone finds it difficult to extract proper political argument from it, and everyone thinks it agrees with them.”

1984 was the book that coined the phrase "Big Brother is watching you", and where once it might have been assumed Orwell was depicting the Soviet Union, Big Brother has taken on broader implications.Especially now that Edward Snowden has made his allegations in the Guardian of the murky world of electric surveillance carried out by government agencies.

"1984 is seen as a great book of the political right that says we should celebrate Englishness, we should conserve the things that make England great," says Robert. "You really feel that when you end up in an antique shop and they’re talking about tea and jam, and things. But the political left proclaimed 1984 as a great book against totalitarianism and fascism.

“But when you get past that, wow, the horror of things like the torture somehow blindsides you a bit to the detail, and it’s quite difficult to come out of the book with a definite sense of what it’s about and what it is trying to do. For me, that’s why 1984 is so much more interesting than Orwell’s Animal Farm, where the argument is really clear, and you can join up all the dots. You can’t join the dots with this; it’s much more complicated.”

Headlong’s adaptation of 1984 incorporates an Appendix, printed at the back of the novel, that is being used to frame a stage version for the first time. It deals with Newspeak, the official language of Oceania, and Robert explains the thinking behind its inclusion in the play.

"We read a letter that Orwell wrote after 1984 had gone to its American publishers, who asked him to make major cuts, including the Appendix, which Orwell saw as essential," he says.

"Once we read that letter, and saw the Appendix, it became very clear that the complexity of the novel rests on the fact that you’re not allowed to rely on things. So if you just take everything in the novel for granted, and put that on stage in three dimensions, you’re doing people a disservice. You are not giving them the same experience as people who carefully read the novel and its Appendix.”

York Theatre Royal artistic director Damian Cruden has suggested the significance of 1984 is not the date itself , nor the book's vision of the future, but its constant resonance in the world around it, whenever it is read or performed.

Now, for example, we live in the electronic age of the internet, with its opportunities to snoop into people’s private lives. Such technology did not exist in Orwell's time, but he defined the possibilities of those prying eyes.

“Orwell is brilliantly vague about the technology involved,” says Robert.

“We had lots of ideas about this originally: we watched The Lives Of Others, a film about the monitoring of East Berlin by agents of the Stasi, the GDR's secret police. You watch the guys with the headphones and the telephone switchboard.

"We had a Lives Of Others version at one time, which inverted the novel, so you wouldn’t watch Winston, you’d watch the people who watched Winston all the way through. That would be great for a while, but it would kill the drama of it when you got to a crucial moment.

“But Orwell just says that they might be watching you; they might be watching everybody, all the time. It’s brilliant, because you’re placed in the same zone as us; not quite knowing whether what we see is trustworthy. There’s no better time than now to think about surveillance, and what it means.”

Does Robert think Orwell be looking down from above, casting his eye over Headlong's interpretation of his 65-year-old text and saying "I told you so"? "Of course I do," he says.. "But what's difficult at times is to know exactly what he’s trying to tell you.”

Headlong, Nottingham Playhouse and Almeida Theatre's co-production of 1984 runs at York Theatre Royal from September 16 to 20, 7.30pm plus 2pm, Thursday and 2.30pm, Saturday. Box office: 01904 623568 or at yorktheatreroyal.co.uk