Great Train Robber Ronnie Biggs will apply for parole next week in the hope of being freed before his 80th birthday, his son said.
Biggs, from Lambeth, London, is currently being held at Norwich Prison but a Parole Board meeting on Thursday will consider his release.
He was a member of a 15-strong gang which attacked the Glasgow to London mail train at Ledburn, Bucks, on August 8, 1963, before making off with £2.6 million.
After being given a 30-year sentence, he escaped from Wandsworth prison, south London, in a furniture van after spending 15 months in jail.
He was on the run for more that 30 years, living in Spain, Australia and Brazil, before returning to the UK voluntarily in 2001.
His son, Michael, 34, said he was "hopeful" that his father would be freed on July 3 - in time to celebrate his 80th birthday on August 8, exactly 46 years on from the audacious heist.
"The meeting is being held next Thursday," said Michael. "We are hopeful that he will be freed but we're trying not to count on the egg before it leaves the chicken.
"I think it's the obvious thing to do. If other people are entitled to get parole, why shouldn't my father? He represents no threat to society."
Michael, who said he was in "constant contact" with his father and intended to visit him tomorrow, said the planned release date would be July 3 - if his bid was accepted by the Parole Board at the St George's Day meeting.
In February, Biggs was taken to the Norfolk and Norwich University Hospital suffering from pneumonia.