My lost son, by Pete Doherty's mother

As the Babyshambles singer checks into the Priory, his anxious relatives ask: 'Where did it all go wrong?'

The troubled rock star Pete Doherty was last night beginning his latest spell in rehab, as his mother revealed that the singer's drug addiction is tearing his family apart.

The Babyshambles frontman has been warned he may face jail, after pleading guilty to possessing heroin, crack cocaine and cannabis on Friday.

He is due to be sentenced in a fortnight, but in the meantime has been ordered by a judge to stay at the Priory hospital and observe a strict 10pm-8am curfew.

Doherty's court appearance came after a night in the cells. It was the latest low in an entanglement with drugs that his mother, Jackie, says made her fear last year that her husband was about to commit suicide.

She revealed yesterday that Doherty's father, a major in the Royal Corps of Signals, also called Peter, has vowed not to see his son again until he is clean of drugs.

"It is ironic," Mrs Doherty told The Times, "because my husband is a record collector. He has 5,000 or 6,000 records and most of them would be by drug addicts. But it is different when it is your own son."

The media interest in the 27-year-old's tempestuous relationship with supermodel Kate Moss had only made things worse. Mrs Doherty, a 52-year-old nurse, whose book about her son is to be published next month, said: "Peter [senior] was sick of the phone going, sick of journalists ringing, sick of being questioned at work."

That was in early 2005, and the situation continued to deteriorate. Just before Christmas, Mr Doherty told his wife to leave home for a week because he needed to be alone.

She was so frightened he was about to kill himself that she warned the padre in the army camp where they were stationed.

In an epilogue to his wife's book, Mr Doherty reveals his pride at his son's early Libertines gigs, but adds: "Peter's greatest misfortune was to become famous. People seem hell-bent on perpetuating his wretchedness - a pathetic, limp figure."

Mrs Doherty writes: "To say that I can fully understand why and how Marvin Gaye's father killed his son [after an argument about the singer's addiction] seems rather dramatic, but the fact is I do understand."

The couple now sleep in separate bedrooms because Mrs Doherty refuses to turn off her mobile phone in case Pete calls in the middle of the night.

"I feel I have to be contactable at all times," she said. "So there is no peace in the house."

Asked if she felt torn between the two men in her life, Mrs Doherty said: "I won't give up my son and I can't give up my husband because I take my vows seriously. If my husband chose to leave me, that's his decision."

The star's two sisters had also suffered. AmyJo had changed jobs and Emily left school before her A-levels to escape the gossip about their brother.

The media circus surrounding Doherty was given fresh impetus this month, with reports that his relationship with Moss was back on. There were even rumours the couple were about to wed, after Moss was pictured wearing a diamond ring.

Mrs Doherty is desperate for them to be left in peace. "They've been deeply in love and people just won't leave them alone," she said. She is also scathing about members of her son's entourage. "Peter is so trusting, but some of them steal from him. They sell stories about him."

On his state of mind, she says: "He doesn't want to die ... He is fragile, but I think he is still a happy soul." But she is aware that others are less optimistic: "I meet fans who never miss one of his gigs in case it's his last."

The fans will be there again next weekend when Doherty is due to perform at Clapham Common in south London.

Bail conditions were fixed to allow his appearance, after his lawyer told the court that preventing it could lead to further lapses in Doherty's condition.

His future may remain uncertain, but Mrs Doherty is clear on one thing: "I could never turn my back on my son."