Campaigners have handed in a petition at 10 Downing Street pleading for a man dubbed "Britain's most violent prisoner" to be released.
Supporters of Charles Bronson gathered 10,000 signatures to urge the Prime Minister to release him after almost 40 years in prison.
The 61-year-old was jailed for seven years in 1974 for armed robbery but has been locked up for much of the time since then following a string of violent incidents, including assault, hostage-taking and damage.
The former bare-knuckle boxer's story was told in critically-acclaimed 2008 film Bronson, which saw actor Tom Hardy in his first big role before becoming a Hollywood star.
Lorraine Etherington, secretary of the Charlie Bronson Appeal Fund, said that the petition aimed to raise awareness of Bronson's case again. She said: "He has served enough time - there are murderers and rapists who get out after serving less time. He hasn't killed anyone.
"Despite completing a violence reduction programme last year he has been denied the opportunity to progress and is still kept in solitary confinement 23 hours a day. He is not a danger to the public - I would argue that he never has been a danger to the public. Out of pure frustration he has tried to get attention by taking hostages and causing trouble, but he knows today that is not the way forward. Despite having a lot of detractors, he has gained an awful lot of support for people who realise that beyond the name there is an injustice here."
Bronson, whose real name is Michael Gordon Peterson, was jailed for life in 1999 for taking a prison art teacher hostage for two days. A judge ordered him to serve a minimum of four years but he has been regularly refused parole and is kept in an isolation cell at HMP Wakefield known as the Hannibal cage.
The petition handed in at Downing Street included a hand-written plea to David Cameron in which Bronson asks to "live what's left of my life and not be buried in the prison system". It also referred to his artistic talents and drawings of his that have been sold for hundreds of pounds.
His supporters are currently planning to launch a third appeal against his life sentence next year, and will put his case to the European Court of Human Rights if that fails.
Tanya Bassett, of the National Association of Probation Officers, told Sky News that the petition to the Prime Minister had little chance of succeeding. She said: "It's highly unlikely he or the Justice Secretary would intervene. There is a thorough, in-depth process for the release of prisoners and decisions are made by the Parole Board."