After two decades at the psychiatric hospital, Albert Haines is making legal history in his bid to be free. Jerome Taylor met him

The patient walks into the room looking nervous. He furtively glances at the ring of chairs in front but only sits down once permission has been sought from hospital staff. He's not used to being able to make his own decisions and he rarely gets an opportunity to meet strangers.

"Can I have a drink?" the man asks, extending a hand to shake. "I'll need it to talk. I do nothing but talk on the ward. You've probably heard I'm excitable. I prefer the word passionate."

Albert Haines has been waiting a long time to tell his story. For the best part of 25 years he has been detained in secure facilities under the Mental Health Act. Much of that time has been spent in Broadmoor Hospital, home to some of Britain's most dangerous individuals, including the Yorkshire Ripper Peter Sutcliffe and the serial killer Robert Napper.

Next week Mr Haines will appear in central London for the first ever mental health tribunal to be held in public after his lawyers won a lengthy court battle to give him that right.

The offence that landed the 52-year-old behind bars bears none of the brutality that characterised many of his Broadmoor neighbours' crimes, though it would undoubtedly have been highly traumatic for his victims.

In May 1986 he walked into a hospital carrying a small knife and a machete, threatened staff before giving himself up. No one was physically hurt and later that summer he pleaded guilty to two counts of attempted wounding. He has not seen the outside world since.

"I know it was a serious offence, that it could have gone either way," he says, his hands wrapped tight around a pair of spectacles. "I am a confrontational person, that's right, but I'm not dangerous."

Mr Haines' dilemma rests precisely on that. There is no doubt he has served a sentence far beyond his so-called "index offence", but until medical professionals are confident that he no longer poses a threat to society he will continue to be detained.

The power to release Mr Haines rests with a mental health tribunal, the secretive system that has the unenviable task of deciding whether someone should continue to be sectioned.

Normally the workings of these tribunals are held entirely behind closed doors because they contain confidential patient information. But Mr Haines, who prefers to go by the name Lazlo, is in the vanguard of a landmark legal case that will give the public a highly unusual insight into the workings of this system.

Broadmoor, in Berkshire, fought the decision to hold next week's mental health tribunal in public, arguing that an open hearing would be stressful for Mr Haines and not in his best interests. They also expressed concerns about the costs of conducting such a tribunal. But the Upper Tribunal disagreed after being persuaded that the right to open justice must be made available to anyone who has the competence to waive their right to a closed hearing.

Of the more than 100,000 mental health tribunals conducted over the past seven years there were just 10 applications for an open hearing. Only one application was previously granted and it was withdrawn, meaning Mr Haines will be the first.

The Independent sought to interview Mr Haines shortly after the paper first reported his legal victory back in February. Who was this man and why was he willing to have his most intimate medical records held up in the public eye?

Reaching him wasn't easy – both physically and bureaucratically. He was keen to talk to us, but Broadmoor was initially wary of letting journalists inside their facility (although they insist they are trying to be more open to the media). After months of negotiations they eventually agreed and allowed us to visit.

The listed red brick Victorian wards tower over the area, although newer buildings have sprung up. Our meeting with Mr Haines takes place in one of the more modern facilities.

A tall man with sunken eyes and salt and pepper hair, he is courteous, but anxious to have his say. In the room with him is a nurse, the hospital's clinical director and a press officer from West London Mental Health NHS Trust.

"I don't want to be involved with mental healthcare anymore," he says adamantly. "I want to be able to recover. I can't support a system that bullies you into being who they want you to be. I don't dispute I have problems, but I dispute that I have mental health problems."

He clearly has a deep distrust of psychiatrists and believes his time in Broadmoor has done little to help him. Much of that is down to the grey nature of psychiatry itself and Mr Haines is particularly unhappy that his diagnoses have frequently changed along with his medication. Doctors had classified him as having a mental illness and psychopathic disorder, but in 2008 they changed the diagnosis to just a psychopathic disorder.

His background is tragically indicative of many inmates at secure hospitals. He suffered sexual abuse during his childhood and was bounced around the care system. In his teens he was in and out of hospitals at a time such institutions were often not capable of adequately treating complex mental health issues in young men. As one official with knowledge of the case admitted: "If things had been done properly when Albert first came in, he might not still be here."

The authorities at Broadmoor admit that it is highly unusual for patients to remain with them for such a long time. Only one in 20 of the 230 or so men held there have been patients for more than two decades. The average stay is six years before people are moved to less secure units and, more often than you might think, out into the free world.

Although Mr Haines has waived his patient confidentiality rights the hospital wouldn't discuss his case in detail – citing that a tribunal is the place for lengthy discussions over potential risks and treatment. But West London Mental Health NHS Trust was willing to issue a generic statement. "Patients with complex mental health problems often find it difficult to engage in the kinds of treatment that clinicians believe is likely to be most helpful; it can be painful and difficult work," the statement read. "Patients may continue to reject any systematic intervention and retain a lack of self insight which obstructs their progress towards recovery, but staff don't give up and are skilled at trying alternative strategies to build engagement."

Much of Mr Haines' tribunal may centre on whether he poses a risk. He is keen to insist that he has not been involved in any major violent incident apart from the fights that break out in a facility which houses highly dangerous people.

"I've had the odd fight, I'm not an angel but I'm allowed in law to defend myself," he says. "It's the nature of Broadmoor that fights do happen."

In the work canteen outside the hospital walls, Kate Luscombe, Mr Haines' lawyer and someone who has visited him every fortnight for the best part of three years, explains her client's case.

"He has been detained for 25 years and has lost confidence in the system. He now seeks a public hearing," she says. "He hopes that this tribunal hearing shall allow an opportunity for public scrutiny of his case and shall maintain public confidence in the administration of justice in mental health cases."

Mr Haines puts it another way: "It's my determination to get myself heard, to get out of hospital altogether and make something of my life with the skills I still have left."

As time is called, a burly male nurse leads Mr Haines back towards his ward. The patient turns around one last time, thanks those inside the room before adding: "Hopefully I'll see you some of you next week."