ALAN Milburn told last night how the pressure of balancing the demands of Government with family life had made him a "deeply unhappy" man.

Speaking exclusively to The Northern Echo at the Department of Health in London, the Darlington MP revealed the depth of his turmoil at not seeing his children grow up.

While speculation was rife last night about hidden reasons behind his shock resignation as Health Secretary, father-of-two Mr Milburn insisted it was simply a "family comes first" decision.

He revealed that the pressure had been growing for more than a year, and the final straw came when he made a 600-mile round-trip last week in one evening to see one of his sons in a school production.

It coincided with him being unable to find time to allow his partner, Ruth Briel, to have tennis lessons on Sunday mornings.

The couple, who live near Hexham, have two boys, Joe, 11, and Danny, six.

Mr Milburn said: "The kids miss me, Ruth certainly misses me. She's unhappy that I'm away, that makes me unhappy. I've become increasingly fed up about it, I've become a deeply unhappy person and I can't do my job as well.

"This has come to a crunch point where I have to make a decision. Am I going to continue with this 24-hour-a-day, seven-day-a-week crazy world of doing this job, or am I going to put the interests of my family first?

"It is a bit of a no-brainer. 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 children are growing up."

Mr Milburn said he intended to stand for Darlington at the next election, although he said even that would be one of the things he would consider during what he hoped would be a long summer holiday.

Yesterday's announcement took everyone by surprise. Even Mr Blair - who had Mr Milburn as a guest at a party to celebrate his 20 years as Sedgefield MP last weekend - only learnt of his decision on Monday.

Mr Milburn's successor is John Reid, a Blairite loyalist with a reputation as a tough enforcer.

The ambitious politician from Tow Law, County Durham, was elected as MP for Darlington in 1992. He was appointed Health Secretary in October 1999, and was talked about as a serious contender to one day replace Mr Blair as Prime Minister.

Mr Milburn's decision - four days before Father's Day - will open a debate about whether Britons, who work the longest hours in Europe, are getting their work/home balance right.

He said: "There isn't a family in the land that has not had to face this sort of choice about how you deal with work and family."

While he secured a huge cash injection into the NHS during his three years and eight months in the job, his departure leaves the Government with hospital consultants in open revolt and the controversial policy on foundation hospitals still at first base.

As Health Secretary, he oversaw a dramatic improvement in services for heart patients, after being moved by the plight of his constituent, Ian Weir, 38, a Darlington father-of-two who died after waiting nearly eight months for an NHS heart bypass operation.

Mr Milburn acknowledged his decision to make heart services a priority was influenced by The Northern Echo's A Chance To Live campaign.

Mr Weir's widow, Maggie, said last night: "I feel that Alan Milburn has been a driving force behind the much-needed changes in the NHS. He's worked tremendously hard to improve the situation for patients, particularly heart patients, who, after all, should be the priority."

Eve Knight, spokeswoman for the British Cardiac Patients Association, said: "I think he will be a hard act to follow. What has been achieved in improving heart services has been remarkable in a reasonably short time."

Colin Morris, chief executive of the Darlington Primary Care Trust, said: "I just think it is a shame he has gone because, in terms of the reform process, we are just at the beginning. He has done a phenomenal amount for the NHS."

John Williams, leader of Darlington Borough Council, said: "We fully understand and support Alan's decision. His achievements have been immense. We are hugely proud of all that he has done both nationally and locally."

Mr Milburn's announcement came on the day his annual leaflet was dropping through letterboxes across Darlington.

Darlington Partnership chairman Alasdair MacConachie said: "It was good for the town to have him in such a position and it helped to put Darlington on the map."

Middlesbrough GP John Canning was less sure of Mr Milburn's legacy.

"He has made a lot of structural changes but here at the sharp end it doesn't feel as if anything has got any better," he said.

Mr Milburn's departure effectively signals the end of the "North-East Mafia" which was once at the heart of the Government, led by Sedgefield MP Tony Blair and featured Cabinet members Peter Mandelson, Mo Mowlam, Stephen Byers, and Nick Brown.

Mr Milburn was regarded as ultra-loyal to Mr Blair who will feel his loss all the more keenly because another of his closest political allies also departed in yesterday's reshuffle.

Lord Chancellor Lord Irvine confirmed he wanted to retire, aged 62, from the Government.