Charles Bronson: why it is time for him to be released

On 31 August, supporters of the prisoner Charles Bronson will deliver a 10,000 signature petition to 10 Downing Street calling for his release. Bronson, now in his 40th year of imprisonment, more than 30 of which have been spent in solitary confinement, is one of the UK's longest-serving prisoners. He has spent more years inside than most convicted murderers or sex attackers ever will – yet he has never killed or sexually molested anyone.

That he has been a problem for the prison system since his conviction in 1974, when he was sentenced to seven years for the £26 armed robbery of a post office when he was just 21, is beyond dispute. By his own admission, he was a handful as a youngster. Prisons do not like people they can't control and Bronson's response to much of what he saw as the system's petty and demeaning treatment of prisoners was violence.

Declared "insane" by a prison doctor in HMP Parkhurst in 1978, Bronson was sent to Broadmoor special hospital for treatment. Forcibly drugged and allegedly beaten, he rebelled by taking to the roof and causing hundreds of thousands of pounds worth of damage before being talked down by his family. Five years of special hospital "treatment" later, he was declared sane and sent back to prison.

Since then, whenever he has felt aggrieved, he has taken hostages: a prison governor, a librarian, and two Iraqis who had hijacked a plane to seek refuge in the UK, only to find themselves subject to Bronson on a day when he was in a hostage-taking mood. (Myths abound about Bronson's feats of strength – that he is a champion dwarf-thrower or that he can bend cell doors with his bare hands. What is true is that he forced one of his Iraqi captives to tickle his feet, explaining later: "I hadn't had them tickled for a while.")

His last hostage victim was prison art teacher Phil Danielson. In Hull prison special unit in 1999, Danielson was tied to a leash and led around the unit, "like a dog". Bronson was cleared of threatening to kill him, but Danielson was so traumatised by what happened that he has never worked since.

For that offence Bronson received a life sentence, eligible for parole after three years. Ever since then he has been isolated in one of the most secure cells in the country, next door to a man who has killed three fellow prisoners. He has been given no opportunity to demonstrate a positive change of attitude or behaviour.

But the time that Bronson has spent in prison is disproportionate to his crimes. He is now being punished simply for being Charles Bronson.