It foretold the future, redefined the gangster's moll, and made a star of its lead actress. As The Long Good Friday is restored for its anniversary, Helen Mirren tells Jude Rogers how it was made

It's been quite a fortnight for Dame Helen Mirren. Last Monday, she won her first Tony for playing The Queen in Peter Morgan's The Audience – something to add to her Oscar, her Olivier, many Golden Globes, Baftas and Emmys. Then it was straight back to Broadway for her weekly haul of seven performances, free time eaten up by rehearsals and brief moments of rest.

But this week, she had to make time for something else too. “I had to,” she says, melancholy clouding those bright, English vowels, as she calls from Manhattan. “I realised that John's gone, and of course the brilliant, wonderful Bob is gone too, so...” She exhales. “I’m the only one left standing, really.”

John is the late British director John Mackenzie, Bob the late British actor Bob Hoskins, and the experience they shared together the making of one of the greatest, most prescient British films.

Restored for a BFI 35thanniversary season beginning tomorrow,The Long Good Friday tells the story of East End gangster boss Harold Shand (Hoskins) trying to become a legitimate businessman – ­albeit with the help of the American mafia.

It also has several astonishing legacies: predicting the eerie transformation of London's Docklands from industrial shipyard to capitalist empire, and Harold Shand's definition of the entrepreneurial Thatcherite spirit before Thatcher had even been elected.

Then there was its effect on Mirren's own career. “It was a very important film for me to be a part of,” she says, with passion. “I loved being in it because I’m a Londoner...and because it was a great learning curve.”

In 1978, Mirren was 33, and already a darling of the stage. Rave reviews had met her Royal Shakespeare Company performances, but her film CV was sparse. A forgotten lead in Michael Powell's last movie, Age Of Consent, plus small parts in Lindsay Anderson's O Lucky Man! and Ken Russell's Savage Messiah did not a movie star make.

Mirren and Hoskins settle down for a smoke in 1980's The Long Good Friday Credit: Film Stills

Then this role came along – as did Mirren's capabilities to make it her own. In the film, Mirren plays Harold Shand's girlfriend Victoria, a very new kind of gangster's moll. Elegant, intelligent, and middle-class, she was more than a match for her partner – not that things began like that.

“The only thing that wasn’t brilliant about the script, as is very often the case, even to this day, is that the female character was very under-realised,” Mirren explains. “Very one-dimensional, very thin. I was there like an appendage.” She said this directly to the film's writer Barrie Keeffe, as well as John Mackenzie, who agreed they would develop her role before shooting.

But when she arrived on-set, she realised that very little had changed.“So I went into the film in a blissful state of ignorance,fighting every inch of the way to drag this character more into the story, make her more proactive. In my ignorance, I didn’t realise you can't really do that – although, in reality, yes, you can change the script the morning that you shoot.”

One assumes that rewriting a female role would have been tough in the 1970s – a period that Mirren recently deplored in an interview for “being worse [for women] than the f______ Forties or Fifties”.

But Mirren has no words of criticism for director MacKenzie or the film's writer Barrie Keeffe. “I’d done very few films up to then, and I was a pain in John Mackenzie's butt, I know I was! But he was a wonderful filmmaker. And Barrie Keeffe's script was one of the best I'd ever read.”

And so they worked together. Victoria changed. Suddenly she was wining and dining the Mafia as Harold tried to find out who bombed his club, and physically restraining Harold after an accidental killing. And there she is after that event, burning his clothes.

Mirren's wishes only succeeded, she admits, because of someone else's support. “Without Bob [Hoskins], it would have been impossible, because he was the star of the movie. If he had been resistant, my cause would have been lost.” Her friendship with Hoskins endured long beyond the film. They last acted together in 2001's Last Orders, while Mirren wrote a moving obituary for him in The Guardian last year. “What he did was an act of great generosity. I think he felt that me developing Victoria would enrich the film, which I think ultimately it did. He was fabulous.”

Bob Hoskins as ferocious Cockney crime boss Harold Shand Credit: Moviestore Collection/REX

On screen, Hoskins is the consummate Cockney kingpin, delivering one-liners with dripping black humour (“You don't crucify people! Not on Good Friday!”, he rails, after his driver is killed). But while he came from North London's Finsbury Park, Mirren was the real Eastender. Her mother, Kitty, was born in London's West Ham, while another relative linked her to what she calls “the underbelly of East End life.” “Bob was the one who came on like a gangster, but I was the one who literally had a gangster for an uncle.”

This was George Dawson, who Mirren describes as “one of the last, pre-Kray brother criminals, more benign sort of East End gangsters”. Does she remember him? “Very well. He was very much a part of my life, Uncle George. I found out doing the film that he was quite a famous character in the East End, because a lot of the old gangsters, these old guys, were around the set.” They appear as extras in a scene in which Harold rallies his many troops. Mirren chatted to them. “I'd be all, 'Did you ever hear of my Uncle George?' 'What, George Dawson?', they'd say. 'Yeah! He went to jail you know.”

She laughs. “But he [came from a time] before things went...well, violence was very, very unacceptable then. You did things through lying and cheating instead. Still, it gave me great cred in the East End for a long while, which I still have to a certain extent.”

This remarkably visceral world came from the pen of Barrie Keeffe, who by the Seventies was a successful TV writer. For The Long Good Friday script, he recalled his time in the '60s as a cub reporter for London's Stratford Express paper, when the Krays were still ruling the East End.

Bob was the one who came on like a gangster, but I was the one who literally had a gangster for an uncle

Two of the film's scenes also come directly from his life: a widow lifting her veil and spitting in his face, and the story of a man being nailed to the warehouse floor. “I interviewed that man in hospital,” Keeffe remembers now, “and said 'What exactly happened?' He said, “Don’t you understand English, son? It was a Do It Yourself accident went wrong!'” And so Harold Shand's patter was born.

As someone who kept in touch with local politics, Keeffe had also heard rumblings about the redevelopment of the Docklands from council officials. These informed Harold Shand's dreams about how the Isle of Dogs could make Britain proud again, and at one point in the film, Harold shows a map of how he'd like it to look.

It's a small gesture towards 2015's skyscraper-filled peninsula, but it's interesting to note that The Long Good Friday's shoot finished in 1979. Michael Heseltine's London Docklands Development Corporation was only created in 1981.

Keeffe had also known Mirren before, when they both were at the National Youth Theatre in their teens (“She was even a star then...[although] I don’t think I ever had the nerve to speak to her!”). He also has fond memories of how Victoria's role was rewritten, and he still salutes Mirren's strength for fighting her corner. “Her performance was absolutely fabulous, and Victoria became the character that held the whole thing together. She became the power behind the throne, the manipulator, in an unflashy way.”

He remembers disagreements with Mirren too, but they got resolved kindly. “Although I think she’d have rather been carrying the machine gun!”

Mirren hasn't seen the film for years, she says, but she still thinks of it often. After all, when not wowing audiences on Broadway, she lives very close to the site of several scenes in London's Wapping. “It was all empty lots and bomb damage back then, and it wasn’t a done deal that it was going to change. There were sort of plans, and thoughts afoot, but nothing was in place, nothing had been realised.”

“So for everything that Bob’s character talks about, actually, came to reality...” The melancholy returns for a minute. “But all cities change – it’s what a city is – but the soul of the city never changes. I do feel that about London. Just as we all did.” 

The restoration of The Long Good Friday is launched at a Q&A at London's Southbank with cinematographer Phil Méheux and writer Barrie Keeffe on Friday June 19