Canon Andrew White's family home is not exactly a rambling rectory, but with its peaceful village setting, immaculately tended garden and homely clutter, it is, by most people's definition, idyllic and utterly conventional.

The problem for Canon White is that he is not a conventional man.

When, as he is occasionally given to do, he opines to his wife, a former lawyer, that perhaps he should be a normal parish priest, her response is always the same. “They couldn't cope with you and you couldn't cope with them,” she tells him.

Canon White is the so-called Vicar of Baghdad. Though nominally he resides in rural Hampshire, his church, St George's, is situated 3,000 miles away, amid the razor wire and bombed-out buildings of Iraq's capital. He spends an average three days a month with his wife and two young sons in the UK; the rest of the time, he is at his home away from home, a Portakabin inside Baghdad's heavily fortified green zone - the six square miles that houses all foreign, military and diplomatic staff in what remains the world's most dangerous city.

This Sunday, an ITV documentary gives an extraordinary insight into Canon White's double life. Rageh Omaar, the veteran Iraq war correspondent, presents him as a charismatic and indisputably brave man.

St George's - the only Anglican church still standing in Iraq - is located a mile outside the green zone. To travel there for his weekly services, Canon White is accompanied by a 20-strong entourage of armed guards. He is clearly adored by his 1,500-strong congregation, who call him their “abouna” - father. But ministering to them is not his sole focus. “I do God on Saturday and Sunday. The rest of the week, I work on reconciliation,” he says.

Part priest, part peace-broker, Canon White was the Church of England's Middle East envoy during Lord Carey of Clifton's tenure as the Archbishop of Canterbury. Today he is regarded as a vital intermediary between coalition forces and Iraq's myriad factions. His work, funded by, among others, the Pentagon, regularly brings him face to face with insurgents and hostage-takers. He has been hijacked, kidnapped and held at gunpoint and the film leaves us in no doubt that, regardless of the flak jacket that he wears with his dog collar, any day could be his last. It is compelling viewing, but it also begs the question: why, particularly as a family man, does he choose to place himself at such risk? My interview with Canon White takes place during his fleeting trip home to publicise, with Lord Carey, an appeal for the five “forgotten” British hostages in Iraq.

It's mid-afternoon and his boys, aged 11 and 9, are still at school. His wife is tending their new puppy. (For security reasons, I'm asked not to name any of them except their cocker spaniel called Rabi.) Canon White is in his study, a room brimming with mementoes of his work and travels.

A collection of crosses - gifts from bishops and other religious leaders - adorn one wall. Elsewhere, awards, including the US Cross of Valour sit alongside photographs of him with Tony Blair and Sir John Major. On his desk are a clutch of mobile phones - he has different numbers for different countries and different contacts - and a half-used strip of tablets. Canon White has multiple sclerosis, a condition that he mostly keeps hidden, the only giveaways being the stick that he occasionally uses for his balance and his voice, which, because of damage to his hearing, has developed a slight drag.

He copes with MS, he says, in the way that he copes with everything: “By keeping going and not worrying about it.” His height (he's more than 6ft) and his sartorial flamboyance (his sober suit is teamed today with multicoloured beaded bracelets given to him by Iraqi children and an oversized silver crucifix) make him a conspicuous presence.

I imagine he must have been flattered to learn that ITV were devoting an hour-long documentary to his work. “Can I be honest?” he says. “I didn't know they were. They told me they were doing a film about Iraq five years on [from the war], and then, at the end, they said, ‘by the way, we've made one about you'.” A check with the ITV press office confirms this.

Now 43, Canon White grew up in Bexley, Kent, the middle of three children. His father was a senior civil servant at the Treasury, his mother didn't work. The family were Baptists, but at the age of 10, White switched to the Church of England after becoming friendly with an elderly housebound lady who was an Anglican. He sounds as if he was a child who knew his own mind. “No,” he says, “I was just odd.” He paints a picture of a boy who was incapable of mixing with his peers. “I didn't do children's things. I was always much more interested in people who were old.” When I ask if his brother and sister were similarly strange, he tells me that his sister was a severe anorexic. Her illness clearly put a huge strain on the family. He recalls his parents taking her to countless doctors and hospitals to get her treated. “She was crazy and because of that I tried to keep away from home,” he says. “Home was not a happy place.”

On Canon White's lapel is a small badge denoting him as a Fellow of Harvard. He's also a Fellow of Clare College, Cambridge. This tickles him because he was never more than an average academic. He wanted to work in anaesthetics, but, realising he would not make it to medical school, elected to train as an operating department practitioner - a skilled member of the anaesthetist's support staff - at St Thomas' Hospital in London. “I loved it at St Thomas' - it was all I had ever dreamt of,” he says. However, one night, having passed his exams, he walked out during a break on his shift, looked across at Big Ben, said his evening prayers “and like a flash of lightning, I was aware I had to go into the Church. I didn't want to. I was so happy at St Thomas', but it was a clear calling”.

Within two years, he had enrolled at Ridley Hall, Cambridge, a theological college. He calls it the “vicar factory”. “When I got there, I realised that the Church was quite boring and irrelevant. No, I knew that beforehand,” he says, mischievously. “I often say that I became a vicar because I was too bored sitting in the pew.”

Canon White is a natural maverick who uses irreverence and self-deprecation to deflect tensions and bypass stuffy protocols. These skills have served him well in the Middle East and, I imagine, they also made him a larger-than-life curate and vicar in Battersea and Clapham, which is where he worked after his ordination in 1990, and where he met his wife.

“I spotted her from the pulpit,” he says. “I was preaching and I thought, ‘I like what I see'.” Six weeks later, he took her out on a punt on the River Cam and proposed. What was the attraction? “It wasn't her cooking,” he says with characteristic flippancy. “But it was love at first sight.”

On Sunday, August 31, 1997 - he remembers the date easily because it was the day Diana, Princess of Wales died - he was chatting to parishioners after morning service at Clapham when two police officers told him the body of his 30-year-old brother Mark had been washed up on a beach in Dover. “He had been diagnosed with multiple sclerosis, but he wouldn't face up to it or take any treatment. Then one day, he disappeared.” The family were never able to establish whether his death was suicide.

Canon White's own MS diagnosis came two years later - a date he remembers clearly because it was the same day that his second son was born. “I was taken to the maternity unit in a wheelchair to be there for his birth. I remember that, yeah...” he says, his voice trailing off. He had been having problems with his vision and balance, and he had known that MS was the likely cause, but the diag- nosis must have been devastating.

“I was upset, I wondered what was going to happen and I could have got really down if I had the type of job where I sat at a desk all day. But I didn't allow myself time to worry.” By then, he had been made a canon - at 32, he was the youngest canon in the Church of England by a decade - and had relocated to Coventry Cathedral, which is the headquarters of the Church of England's International Centre for Reconciliation (ICR). He was appointed the ICR's director, a role that took him out of mainstream ministering and into the world's conflict zones. His predecessor had worked mainly in Eastern Europe, but he switched the focus to the Middle East, spending time in Israel and also Baghdad, which he first visited in 1998. His appointment as Lord Carey's peace envoy soon after consolidated his status as a mediator.

The ITV documentary films him with Dr Mowaffak al-Rubaie, Iraq's national security adviser and with Ayatollah Hussein al-Sadr, the uncle of Iraq's most notorious insurgent Moqtada al-Sadr. Their talks look slightly staged for the cameras, but there is no question that he commands respect, both from the Iraqis and the coalition forces, to whom he preaches in the American chapel.

Canon White never met Saddam Hussein, but he did, he tells me, once have an uncomfortable dinner with his two sons at the behest of a trusted contact. “He told me that they had said they would kill him and his family if I didn't go - so I went.”

His most dangerous work is as a broker in hostage negotiations. Over the past few years, he has intervened on behalf of about 160 hostages of various nationalities. Two years ago, at a rendezvous just outside Baghdad with the kidnappers of a Brazilian, he describes being held in a room for several hours where chopped-off fingers and toes littered the floor. “They were quite fresh,” he says, when I press for more details. And how did he get out unscathed? “I gave them money. About $35,000.”

There is a swashbuckling tone to these anecdotes that makes me wonder if Canon White isn't a bit of a war junkie. “I have problems coming home. I lie in bed at night and there are no bombs, no rockets, no helicopters. It's pretty boring,” he says. But then he tells me something else - that explains much about the choice he has made. “Three years ago the Church of England told me that I was too ill to carry on working. There was no longer a place for me in the UK, but I was already working in Baghdad and that is one of the main reasons why I've ended up there.”

He set up his own peace resolution organisation - the Foundation for Relief and Reconciliation in the Middle East (FRRME) and threw all his energies into restoring St George's, which had been rendered a shell by the war. Christians represent around only 3 per cent of the overwhelmingly Muslim population in Iraq, and they used to be members of the country's middle class. But today they rely on the church's support for the most basic necessities. “Their fathers have been killed. They have little food or water and no medical help. We have to provide for them and we do.”

He had hoped that he would be able to move his wife and children to Iraq with him, but there is no realistic prospect of that. When he's away, he misses them and speaks to them on the phone every dayand his wife offers him unstinting support.

This summer he plans to return for an extended holiday with six Iraqi children from his congregation, who his wife will help to accommodate. What Canon White doesn't tell me, but a member of his staff does, is that Mrs White is a complete brick who understands that her husband is better off in a place where it is normal not to be normal. At home, his ill-health is only exaggerated. His MS means that he cannot drive; nor can he easily kick a rugby ball around their garden or join his sons on the trampoline. Our cooler climate also exacerbates his symptoms. In Iraq, the warm temperatures make him feel better, and he has the added, immeasurable, satisfaction of knowing that he is making a difference.

The downside to this, of course, is that he might be killed. But through family tragedy, debilitating illness, and war, Canon White has learnt that getting on with living is better than worrying about dying. “For me, it's very blurred - the line between life and death,” he says. The Vicar of Baghdad: Through the valley of the shadow of death “As a Christian, I know when my time is up, it's up. But nothing will get me until then.”

The Vicar of Baghdad, ITV1, Sunday, 10.45pm (www.frrme.org)