The knives are out: How Blade Runner was plagued by rows between its director and star

In hindsight, it is no surprise that the set of Blade Runner (1982) was so unhappy. In one corner was Harrison Ford, at that stage the most bankable star in movie history. "James Stewart, Humphrey Bogart – I don't care who you put up there. This guy was generating more box-office dollars than any human being ever," says his co-star in the film, Edward James Olmos. "He'd done Star Wars, The Empire Strikes Back and he'd just finished Raiders of the Lost Ark."

In the other corner was the British director Ridley Scott, the ex-art school student from South Shields who had by that stage directed more than 2,000 commercials and a pair of highly respected feature films, The Duellists (1977 ) and Alien (1979).

Scott was used to having his own way – but so was Ford. On most of his movies, Ford was treated with kid gloves. Directors would fawn over his every move, cater to his every whim. That wasn't Scott's method. "Do it again," he'd gruffly tell his star. It wasn't his habit or inclination to flatter his actors. Besides, Scott had his own battles to fight with the Hollywood studio bosses and wasn't about to defer to his leading man.

"My sets are usually hilarious, great fun, and everybody wants more," he protests at the idea that he is an autocratic film-maker. "I had already done The Duellists. I had already done Alien. All those were happy sets and I was two and a half thousand commercials in – probably the most successful commercial maker of that day. I know how to run the floor. But in Hollywood, I was a new kid on the block."

Scott regarded the studio bosses as interfering control freaks. He didn't blame them, though. After all, making a sci-fi epic like Blade Runner was an immensely risky and expensive endeavour. Any false step that Scott might make could cost the studios millions of dollars. They therefore questioned every decision he made. Scott's reaction was to snap back. As he says today: "The only way I could get through this was literally to drive the bus – so I drove the bus and I don't think it was a very happy set."

Ford's discomfort was evident. "He did not like that picture. He never liked it," says Olmos. Adding to his discomfort was Ford's lingering sense that perhaps it had been a mistake to accept the role of Rick Deckard, the replicant killer. This was a man who beats up and kills women: a futuristic version of the kind of private eyes you find in Raymond Chandler and Dashiell Hammett, but also a character with a very dark side. Whatever else, Deckard was no Indiana Jones.

In September, when Warner Brothers organised a press junket at the Venice Film Festival to celebrate Blade Runner: The Final Cut, a 25th anniversary version of the film, almost the entire cast seemed to be in attendance: Sean Young, Rutger Hauer and Darryl Hannah were all there, as was Scott. There was no sign, though, of Ford. The film is clearly a source of torment as much as of pride to him. Perhaps that is why his performance still registers so strongly. There is a bristling intensity – a sense of a barely suppressed anger – that you do not find in his more conventional action hero roles.

Still, Scott says that he had little idea a quarter of a century ago just how influential Blade Runner would prove. It had been a difficult production, but after his battles with the studio and his difficult star, he had moved on. As he puts it, he didn't have "sleepless nights over the film".

Back in the 1980s, Scott was much in demand as a director of pop promos. He couldn't help but notice that band after band kept on talking about Blade Runner. "It's always interesting how rock and roll gets it faster than anyone else," he says today.

Then, he discovered from Warner Brothers that Blade Runner was the second most requested title in its entire library of films, behind only Casablanca. In the early 1990s, the film was shown at the Santa Monica Film Festival. By mistake, someone had sent an old 65mm preview copy rather than the version originally released. Suddenly, the audience realised that this wasn't the film they knew. Scott credits this screening with sparking the interest of the studio in releasing a new version of the film.

It is one of the ironies of the DVD era that the same Hollywood companies that imposed their will on reluctant directors are belatedly allowing them to have their way. The "director's cut" works for everyone – it gives the film-maker the chance to fulfill his or her original vision, while providing the studio's home entertainment arm with a new product to market.

Scott's first director's cut of Blade Runner was released in 1992, without the voiceover or the happy ending. Now, it is being seen again in a restored, remastered version, featuring previously unreleased and extended scenes, and new, improved special effects. In truth, though, the essence of the film has never changed. This is a story about technology threatening to annihilate humanity. It portrays Los Angeles in 2019 as a dystopian metropolis, dark, brooding and dirty.

You can't exactly call the film (based on Philip K Dick's novel Do Androids Dream of Electric Sheep?) prophetic. The idea of a grim futuristic world controlled by big, bad corporations was already a cliché in 1982. Scott has also always acknowledged that he owed as much to Raymond Chandler-like private eye yarns as to sci-fi in the way he shaped his story.

Even so, Blade Runner seems as topical as ever. Its premise is that the Tyrell Corporation's replicants – or cyborgs – are being used as slave labour "off world" and, after a rebellion, have been declared illegal on Earth. At a time when Western countries are terrified of potential terrorists in their midst and of foreign labour stealing jobs, this storyline has a strange new resonance.

One actor for whom the film has never lost its mystqiue is Hannah. While others in Venice recalled a difficult and sometimes fraught production, she spoke in openly nostalgic terms of her experiences as a teenage actress on Blade Runner. "It's my favourite film that I have ever been in. My inspiration to be in movies was to live in another reality, and in this case it was built for me to the most detailed, beautiful extent. The sets were exquisite, the costumes were exquisite," she said as she proudly displayed a scar on her elbow from one of the scenes in which she slipped on set fell through a window. "I didn't have to work at all to be transported to another reality."

Hannah's remark is instructive. The reason that Blade Runner is still being talked about 25 years after it was made is precisely that it takes viewers into a bewitching but highly unsettling futuristic world.

Warner Brothers is promising that the new version is the final and definitive Blade Runner. Scott, it seems, is not so sure. "It's like finishing a painting – you never really do," the former Royal College student says, adding that there is always room for improvement or re-thinking. "You still walk into a room and look at it."

'Blade Runner: the Final Cut' goes on limited release on 23 November; the special edition DVD is released on 3 December