After his shock resignation as Health Secretary yesterday, Darlington MP Alan Milburn talks exclusively to Political Editor Chris Lloyd about why he quit the Cabinet.

ONE o'clock in Whitehall. The news is out and a gaggle of photographers is gathering outside the Department of Health to capture it, although the evening newspaper is still running with the line: "Cabinet reshuffle - few surprises".

Deep inside the monolithic Department of Health, father-of-two Alan Milburn is clearing his desk. His computer screen is blank, and there are just the photographs of his kids and their felt-tip drawings that remain to be removed.

"I've got to get out quick so they can fumigate the place before the next person moves in," he quips.

He knows stories are already circulating about why he is moving out even though the ink is barely dry on the resignation letters he has exchanged with the Prime Minister. He's in financial ruins; he's had a catastrophic bust-up with his close friend Tony Blair.

"And I'm having so many affairs that it is no wonder I am exhausted with large bags under my eyes," he says.

It's another gag. He insists time and again that there is no scandal about to break, no skeletons about to be unearthed, no jump before a push.

"There are going to be wild conspiracy theories about whether it is personal, political, financial, sexual or all together," he says, sitting on a sofa in his palatial office. "But it has nothing to do with anybody else. It is perfectly simple."

The family-versus-career battle has been raging for more than a year, with him 250 miles away from his partner Ruth Briel and their two boys, Joe and Danny, aged six and 11, who live near Hexham.

Last week, he caught an evening train up from London to see a school play and returned on the early morning red-eye service to be at his desk by 8am.

He promised Ruth that he would look after "the kids" from 10 to 11am every Sunday morning while she had eight tennis lessons - she had to cancel four because of his non-availability.

"Something came up, something important," he says. "There's Iraq happening or the euro and you have to be talking to people, talking to the media."

They considered moving to London, but didn't want to sacrifice "the kids'" quality of life.

'It was boiling down to a choice," he says. "Am I going to continue with this 24-hours-a-day seven-days-a-week crazy world or am I going to put the interests of my family first.

"Something has to give. This is not a dry run, this is your life. You only get one crack at it and you only get one chance to be there when your kids are growing up.

"For Danny, I have been a Cabinet minister for the whole six years of his life. I've been away for them. For Joe, who's nearly 12, I've been away half of his life and I don't want to miss any more of it."

Then came the pre-reshuffle speculation with talk of him moving to education or trade or even Foreign Secretary.

"It filled me with dread because if any of these stories were true, I'd move to another job where I'd have to work even harder to dig myself in and that was the last thing I needed," he said. "I had to go and bite the bullet and tell Tony."

On Saturday night, he was dancing to Mr Blair's guitar-playing at the Prime Minister's 20th anniversary party in Trimdon; on Monday morning, he was banging on No 10's door.

"Tony was utterly and totally brilliant," says Mr Milburn. "He was - what's the right word - he was big, really big. I have created a problem for him, but he didn't want to talk about that but about whether it was the right decision for me, for Ruth and the kids."

He takes a bite out of his lunch: a single piece of sliced white bread with a thin coating of strawberry jam smeared across it. He appears wearily relaxed, rather like a schoolkid on the morning of the last exam: it's been a long term, the whole summer stretches before him, there's just one last gruelling test to get out of the way. For him, that test is his last appearance as a minister before the media.

"I've got to discuss intensely personal things about me, my children, my family, my life, with people I don't know and they are going to be beamed to millions of people I don't know," he says. "I don't really like that. And I have to deal with all the conspiracy theories, but I don't give a damn what people think, I really don't."

The conspiracy theories seem wider of the mark the more he talks. He doesn't even appear to know where he'll be at the time of the next election.

"Representing Darlington has always been hugely important to me and my intention at the moment is that is what I should continue to do," he says. "Obviously, I've got to think about these things. My game plan is that I'm going to have some time off, a decent - hopefully long - summer break, get rested and think about what it is I want to do. But whatever it is, it will be with a clearer focus on things that are really important, and it will be a big change."

He finishes: "I haven't got a plan. I dunno."

He is, of course, only 45. In ten years, Danny will be 16 and Mr Milburn will be young enough to have another crack at high office.

"I think it is very, very difficult having left in these circumstances to return, and I really can't see it," he says. "I have never sat down and worked out where I would be within a particular timescale.

Mr Milburn was born in Birmingham but never knew his father. His mother, Evelyn, moved back to Tow Law, and then on to Newcastle and Stokesley. He studied history at Lancaster University, started a PhD at Newcastle, but dropped out when he caught Communism.

In 1986, he led the campaign to save the Sunderland shipyards, but their closure showed him that old-style socialism had had its day. A new Labour movement was required, and in 1992 he won the nomination for Darlington - his neighbour in Sedgefield was Mr Blair, the architect of New Labour.

In opposition, Mr Milburn made his name as shadow health spokesman with probing, detailed Parliamentary questions. Following the 1997 Labour landslide, he spent a year as junior health minister and a year as Chief Secretary to the Treasury before he took over as Health Secretary when Frank Dobson had the misfortune to be chosen as Labour's candidate in the London mayoral election.

Like the doomed Dobson, Mr Milburn also appeared to have been handed a poisoned chalice. But, either by luck or a lack of a flu epidemic, he has taken the NHS off the critical list - no longer are Britain's winters filled with horror stories of patients dying on trolleys.

"Part of the reason I can walk away is that I think I've helped get it into a position where it is moving forwards. Beds growing, nurses growing, hospitals going up, waiting times falling, health outcomes improving, cancer death rates falling.

He recalls how his first project as Health Secretary was motivated by the death of his constituent, Ian Weir. "When I started we were asking NHS patients to wait up to 18 months for heart operations, and now we have halved that," he says. "It was the first decision I made, and it mattered to me because of Ian and I wanted to put it right."

His biggest achievement, though, is forcing the Treasury to increase its spending on health for the foreseeable future. "We had to put the NHS in terms of its funding on a medium term secure basis and I've done that and I'm very pleased. Without the money it just isn't going to improve," he says.

This security was won after a battle with Gordon Brown, and one of the conspiracy theories is that he has been forced out by the mean Chancellor.

Those theorists will find further evidence in his last sentence, a protestation of support from the backbenches.

"We should be proud because we have a really good government and an amazing bloke as Prime Minister," he says. "There is nobody in the Cabinet who can lay a glove on him. He towers, I think, both politically and personally, over British politics and I will continue to support him."

It's nearly four o'clock, and he disappears to face his last gruelling test in front of the press pack.

Further down Whitehall, the evening paper has caught up with the news - and the theories. "Shock Cabinet exit," it shouts from the newstand. "Health Secretary cites family but rumours point to Brown."

Politician quits to spend time with family just is too boring to be newsworthy or believable.