London - Ronnie Biggs, the "Great Train Robber" who challenged the authority of the British state with an audacious robbery, a prison escape and more than 35 years on the run, has been freed from jail, the government announced Thursday.

In a potentially embarrassing U-turn, Justice Secretary Jack Straw said that Biggs, who turns 80 on Saturday, had been granted release from jail on "compassionate grounds."

As recently as July 1, Straw had ruled that Biggs would not be freed on parole because he had been "wholly unrepentant" about his 1963 raid on a postal train and the more than three decades on the run from British police.

But Thursday, Straw said his new decision was based on medical evidence that Biggs' condition had deteriorated and he was not expected to recover.

"I made the decision to refuse parole principally because Mr Biggs had shown no remorse for his crimes nor respect for the punishments given to him and because the Parole Board found his propensity to breach trust a very significant factor," Straw said in a statement.

"In this case, I have had to consider the medical evidence against well-established criteria - specifically whether death was likely to occur soon and whether the prisoner was bedridden or severely incapacitated."

"The medical evidence clearly shows that Mr Biggs is very ill and that his condition has deteriorated recently, culminating in his re-admission to hospital. His condition is not expected to improve," said Straw.

"He is being released effectively to die and that cannot be considered a victory. But it's a victory for common sense and Mr Straw has made the right decision," Biggs's legal adviser, Giovanni Di Stefano, said Thursday.

Biggs would stay in hospital, the lawyer said.

Biggs' son Michael, who has campaigned tirelessly for his father's release, said he was "absolutely delighted" and hoped that his father would survive long enough to see his 80th birthday.

Ten days ago, Biggs was transferred to hospital in Norwich, eastern England, from his prison in the city, suffering from "severe pneumonia," prompting a fresh appeal by his son for his release.

The decision was criticized by some Labour Party members and human rights groups who urged the government to show compassion.

Biggs has suffered several strokes since his return and is unable to eat, walk or speak without help, his family says.

Biggs was a member of a 15-strong gang which attacked the Glasgow to London mail train in Buckinghamshire, north of London, on August 8, 1963, getting away with 2.6 million pounds, a record haul at the time.

He was given a 30-year jail term but escaped from London's Wandsworth prison after 15 months, eluding capture by Scotland Yard for more than 35 years.

During that time, Biggs lived in France, Australia and Brazil, from where he returned voluntarily in 2001.(dpa)