The English civil war drama To Kill a King was so cash-strapped, its star had to pay to have the set removed from Hampton Court. Stuart Jeffries was there

It's a bitter Tuesday in February at Hampton Court Palace and Olivia Williams is having a break from filming a key scene in the English civil war drama To Kill a King. She plays Lady Anne, wife of the commander-in-chief of the parliamentary army, Sir Thomas Fairfax. The history books recall Lady Anne as a spirited woman, who disrupted the trial of Charles I because she did not believe mere mortals like Oliver Cromwell had the right to end the life of a divinely installed monarch. Director Mike Barker demands take after take of a scene in which she and Fairfax (played by Dougray Scott) confront corrupt Baron Denzil Holles (James Bolam) to try to thwart his scheme to help Charles I rob the Treasury and bring the English revolution to a quick end.

Like the fitting of Williams's corset, the making of this film has demanded a series of painful squeezes. The history of To Kill a King is one of unpaid wages and bills, corner- cutting, reshooting and rescripting on the hoof, computer-generated miracles, bafflingly complicated funding deals and bankruptcy, not once but twice. It's also a rare story of a British film made without public financial backing.

The saga began three years ago when a novice scriptwriter called Jenny Mayhew wrote a promising screenplay set in the aftermath of the first civil war in 17th-century England. Her focus was the relationship between Fairfax - who led the parliamentary forces to victory against the army of Charles I (Rupert Everett) - and Oliver Cromwell (Tim Roth), the leader of parliament and later Lord Protector of England. After a wartime friendship, Cromwell and Fairfax clash over key political decisions - notably what to do with the king - as they decide how to build a new England. Fairfax refuses to sign the king's death warrant, thus ending the friendship between those historically rare beasts, two English revolutionaries.

The first thing you notice about To Kill a King is the lack of battles - not even the key Cromwell 1645 victory at Naseby, which ended the first civil war. Producer Kevin Loader explains: "The opening credit sequence is set at Naseby's aftermath, so there are bodies on the battlefield and the friendship between Fairfax and Cromwell is made clear. But I think the narrative of a battle is quite difficult to translate to a film and actually not that interesting. Onscreen battles have to be incredibly simple or you can't understand them. Like in Braveheart - there's a load of blokes on the left of the screen in blue woad and there's a load of blokes on the right with pointed sticks and they're going to meet in the middle."

The other reason is that its budget was just over £12m. Braveheart's, for example, was £46m. "We couldn't really have 20,000 people running down a hill like in Braveheart," says director Mike Barker. "Not least because we only have four extras." Ewan McGregor, the original Cromwell, dropped out, as did Emily Watson, who was going to be Lady Anne. But the real problems started soon after filming began in January. By then, producer Loader had roped in his old chum Mike Barker to direct. Surrounded by a cast he admired and a crew he had painstakingly assembled, Barker set to work and things went smoothly, boosted by English Heritage allowing filming to take place at Hampton Court Palace for the first time. "We were very persistent and diplomatic in our approaches," says Loader.

Rupert Everett was beheaded at 2pm on January 30 in their simulated scaffold, just as Charles had been in 1649. On the day I visited the set, it all seemed to be proceeding very nicely. Then it all went wrong. "What happened," says Barker, "was that the film went bankrupt once because the finance that was meant to be there wasn't, so no bank or bond would cover it - and without the bond, you can't do the rest of your finance. There's no guarantee that there will be a film at the end of it." Barker bore the consequences of this funding collapse and suspended filming. "On the last day of filming, when we went bankrupt, we didn't even have enough money to remove our 200ft set of Whitehall Palace from Hampton Court. We'd dug all the lawns up and we couldn't replace them because we couldn't pay for turf. I mean this is the Queen's palace! It was really embarrassing. Dougray came up with the money to pay for the set removal."

Jeremy Thomas, producer of Crash and Sexy Beast, helped rescue Barker's film by putting together a distribution deal to allow the film to continue shooting. "It's been a really fraught time," says Barker. "When it went down the first time, I was sure we'd get it up and running again. But when it went down the second time, I didn't believe it would ever get made. This is the first time in history that a film has gone bankrupt twice and still got made."

But the deal forced the film-makers to cut the picture's budget and the name of the film was also changed from Cromwell and Fairfax to To Kill a King. With new money pledged, Barker started filming again. "The hardest thing was we had to save several million quid off the budget, mid process, which is very hard because you've shot half the film and so you've got to rework what you've got to make sure it works with the rest of the film."

Barker and his faithful 200 cast and crew started working again on location in Dover in the spring. "We knew the money was coming in, but at the end of three weeks, all the crew were paying their own per diems - that's all the dinner money and stuff they get when they're away from home. It was like an army that hadn't been paid, and it should have got ugly, but they were fantastic. After three weeks, the money still hadn't come through and many felt uncomfortable going into the fourth week unpaid. I realised we were going to lose the film, but we were so close to getting the money. I knew it was coming but it was so difficult to prove it. We had been let down so many times.

"I went round cast and crew and said, if you all agree to stand down and not get paid while you're stood down, we could possibly resurrect it, and that's what happened. They stood down for another three weeks then we got the film going again for a second time. And this time we pulled it off."

Not least Scott, who put up £70,000 of his own money to ensure that the film, on which he had been working as an associate producer for two years, got made. And it did get made, with money from an extraordinary range of sources, most of them foreign. "I've had to add about 30 seconds to the producers' credits because so many people came in with £50 here and £100 there. It's the longest title sequence in the history of film-making," says Barker. But neither the Film Council of England and Wales nor any other public body appears on that list. "There was a time when they could have helped us out but they chose not to, which we were all very disappointed about, especially when it was a British cast, a British crew and British subject matter. Also, if we'd gone down, we'd have owed a lot of money. It's a shame they didn't bail us out."

The few scenes that Barker and his editor allow me to see look solid enough, and I feel a lump rising in my throat when Everett says his last words and when Roth later holds aloft a hand covered in the beheaded king's blood and yells to the crowd: "With this you're subjects no more, but citizens!" As Barker sits in the post-production studios in Soho on a hot summer day, he realises his film has gone through many more revolutions than England. "I found it really exciting, to be honest. I made it into something of a political thriller almost out of necessity with Fairfax and Cromwell going after the guys who try to corrupt their revolution. The whole turmoil made me kind of buzzy."

At one point, he recalls, they were filming Charles's trial at the Bodleian library in Oxford, but lost the location because lack of funds forced them to stop filming. "So we went to Harrow school at the last minute and filmed it there. And using tricks and stuff, we managed to make it look like the sequences we'd filmed in Oxford. We had to do that sort of thing again and again."

Barker's film is scheduled for release next year. "I've suffered a lot in its making," he says. "But I feel I am now a really ingenious film-maker."

© Guardian Newspapers Limited 2002