DORSET isn't a million miles from the sweaty, swampy southern United States. But, on a fresh autumn day, with the cool air tumbling around the remote cottage where Clive Stafford Smith now lives with his wife, Emily, and their retriever, Mel, it must feel like it.

Clive - lanky, shaven-headed, and wearing a crumpled sweatshirt - looks more like a student than one of our most high-profile human rights lawyers. The only clue to his business is the hum of his old printer, piling out pages and pages of a legal document.

Clive has defended more than 300 Death Row inmates over the past two decades. He has lost only four of his cases. And, yes, he has attended executions.

"I always go to executions. The client wants you to because you are usually the only person there who's on their side," he says. I ask him if any in particular sticks in his mind. No hesitation. "Nicky Ingram. They tortured that poor guy to death."

Ingram was sent to the electric chair in April 1995 after being found guilty, on shaky identification evidence, of murdering a man during a robbery when he was 18.

Clive had met him some 12 years previously although, as he likes to point out, they were both born in the same maternity ward in Cambridge.

"Nicky was set to die on Tuesday at 7pm. At 6.30pm they got a stay from the Federal judge but they didn't tell him about it, and they went ahead anyway, and shaved his head and the bit on his legs where they attach the electrodes. Then the execution was back on and they killed him."

The details of what happens in the electric chair - the leather restraints, the taped-up mouth, the hood to mask the contorted face, the way the prisoner's head is strapped to a pole to stop it thrashing around and discomforting the witnesses - are well documented. It is still the execution method of choice of six American States. And Clive is reluctant to go over them again, which is understandable, because he considers Nicky Ingram as his friend.

However, he wants to point out that the muted, official details of what happens during the process, the "electrocution-eering" of the penal system, so helpfully printed out for the journalists attending, are "absolute rubbish".

He hands me a printout of what an execution witness in Georgia has observed. It says: "When the executioner throws the switch that sends the electric current through the body, the prisoner cringes from torture. His flesh swells and his skin stretches to the point of breaking. He defecates, he urinates, his tongue swells and his eyes pop out. In some cases I have been told that the eyeballs rest on the cheeks of the condemned. His flesh is burned and smells of cooked meat. When the autopsy is performed, the liver is so hot it cannot be touched by human hand."

"What they did to Nicky was absolutely disgusting," he says.

I start to sympathise with him but he's not into self-pity. "It's not what's happening to me, it's them; they're the ones who have to go through with it."

But why does he go through with it; labouring away in this squalid corner of the American justice system?

It can't be the glory; "They think I'm an interfering colonial, come to tell them what to do."

And it isn't the money; unlike the Cherie Booth brand of bright lights/fat fee human rights lawyering, Clive lives on "charity, basically".

Did he have a Bob Geldof moment, then, and feel that he, personally, could make a difference?

"Yes. No. Well, I don't know exactly. I got infatuated with the death penalty when I was a kid. This is kind of apocryphal, but I remember when I was very young, about 12, learning about Joan of Arc who, in all the pictures, looked a bit like my sister.

"Anyway, until that point we'd all read about Agincourt, and the rest of it, and cheering on the English, and it struck me as quite outrageous that we were burning this poor girl. That sort of interest took me until I was 16, when I wrote a paper about the death penalty and I was horrified to learn that in America, they still did this to people."

After leaving posh Radley College, he seized the opportunity to study in America, intending to become a campaigning journalist. Then he spent six months meeting inmates on Death Row.

"It horrified me to discover that if you are on Death Row, you don't even have the right to a lawyer, you have to represent yourself unless someone agrees to help you, and I quickly realised that instead of journalism, perhaps I should get a law degree, instead."

He learned fast. He had to because "the first person I supposedly helped, the first person whose case I tried, I had only been out of law school for six months. I was just 24. It was unbelievable that someone with such a lack of experience was allowed to represent at a trial like that. In Britain at that stage of your career, you'd be looking after something like a shoplifting. It was scary."

Tales of inadequate, incompetent and downright appalling defences abound in the US justice system. They are a stark vindication of Clive's belief that those without the capital to defend themselves frequently end up with the punishment and that the whole system is founded on the "politics of hatred".

"I remember one of our cases, involving a man called Alfred Leatherwood. At his original trial he was represented by a law student doing a stint in court. At the beginning of the hearing she asked the judge if she could have a minute to compose herself, because she'd never been in a courtroom before.

"Alfred hadn't even murdered anyone. He was a mentally defective 18-year-old, charged with inappropriate touching of a 12-year-old girl. We got him a new trial, old Alfred, and we got him out. I didn't feel so bad about myself after that, because the standard of defence for most of these people is abysmal."

Another of his clients was a man originally defended by the famous "Sleeping Lawyer". "This guy literally slept through much of the case. And, in the appeal, it turned on whether he was actually sleeping or just dozing. That was what they argued about!"

Then there's the case of Englishwoman Linda Carty, whose appeal is coming up in November. "She was originally represented by a guy who is so bad, he's got 21 clients on Death Row. He has more people on Death Row than something like 25 states put together."

They're also representing a case in Alabama, where the defendant's original lawyer hadn't even met him until a day before the trial.

This outrages Clive, because he believes you can't run a proper defence until you know your client, and he deplores the lawyerly belief that you should not become emotionally involved in cases. "You have to like the person you're representing. If you don't, you can't represent them," he insists.

The extent of Clive's personal commitment was made crystal clear in the landmark documentary Fourteen Days In May, broadcast in 1987. It followed his desperate attempts to save Edward Earl Johnson from execution and then his quest to prove his client's innocence, after his death.

Executing the innocent does, of course, happen. The House Judiciary Subcommittee on Civil and Constitutional Rights reported that from 1970-1993, 66 people were released from Death Row with evidence of their innocence. Other researchers found 23 cases from 1900 to 1992 where innocent people were executed.

"The problem with the stereotype of prisoners on Death Row is, for a start, that they're all guilty," says Clive. "Most of them didn't do the crime they're accused of, and the others are usually insane." One of his clients had an IQ of 54 and, says Clive, happily confessed to killing Presidents Abraham Lincoln and John Kennedy.

But it's not just the clients - many of those delivering US justice are not the full dollar. Clive remembers the day he stood in a Southern states court building, interviewing potential jurors. "Out of 162, 109 said they'd execute my client even without a trial, which seemed a little extreme."

Then there's the Louisiana executioner he got into a public debate with, asking him if he would execute a 15-year-old. "He said he would. So I asked if he'd execute a five-year-old. Yes, he would. Then I asked him about his grandson, who was five, and if he would execute him, and he said yes. I found him fascinating. I'd like to have done a study on him to see what makes him tick."

Not too difficult, then, to see why he quit the US.

"The thing about America that I just can't deal with, is why people seem to hate each other. It's a society where so many people are full of dislike for each other," he explains. "In the end, I had to leave."

The work at his Justice Centre in New Orleans will go on, supported by Reprieve, the British-based charity he set up to support his Death Row work. "We get people to come and help us for three months at a time, internees, I suppose you'd call them, although we call them 'exploitees' because they do all the hard work and I get the credit," he jokes.

He's still representing Krishna Maharaj, the Asian businessman in the news recently who has languished for 18 years in prison, many of them on Death Row, for murders he almost certainly did not commit. And he'll be busy enough with his new endeavour - Justice in Exile - helping Britain's Guantanamo Bay detainees.

All this is admirable but none of it explains his fervour; why he cares so much.

Does he believe in God? "That's a loaded question." OK then, does he have a religious belief? "He shifts, impatiently. "Everyone believes in God." But does he; is that why he strives to uphold the Sixth Commandment?

He explains that when he was at school, he went to church "all the time"' and decided he'd attended enough. But, he says: "There are times in court when you have to stare very hard at the people who say 'Kill him' and quote Matthew Chapter 5 Verse 7: "'Blessed are the merciful because God will be merciful towards them'."

He asks me if I have siblings and if I would ever consider sending them to prison. I tell him I would, if the crime was terrible enough. "Well," he says, confidently, "No matter what you say, I can tell you now, you wouldn't."

He wouldn't. In fact, he wouldn't send anyone to prison. "We are all much more than the worst thing we ever did. Would you like to be judged as a person on the worst thing you have ever done?"

With his shorn head, intense eyes, and passionate conviction of the rightness of his cause, I am suddenly reminded of St Joan. If the poor girl had had Clive Stafford Smith to speak up for her, she might well have lived. He is, quite simply, extraordinary.

If you want to help

Reprieve provides effective legal representation and humanitarian assistance to impoverished people facing the death penalty at the hands of the state in the US and the Caribbean. If you'd like to get involved in the campaign to free Krishna Maharaj and Linda Carty, or know more, log on to www.reprieve.org.uk or call Andie Lambe on 0207 353 4640.