I first took heroin in 1969 or 1970 when I was 15 or 16. We were told in those days that all drugs were drugs and it didn't really matter what you took. It was the 'in thing', the normal thing then, it was quite free and open, there were no laws about pot and you could easily get private scripts for heroin from the doctor. I was working with my dad one time and took my mate in and he said: "How was the acid this weekend boys?" People didn't take any notice back then. I used heroin off and on for years and didn't get a habit.

I stopped in the early 70s, but in the early 80s my wife died of a brain tumour. I also could have had custody of my daughter [from another relationship], but her mother told her, "your dad doesn't want you", and took her away. I started using then and after that I couldn't get rid of it. I didn't think it would be, but it was really easy to get a habit.

About 10 years ago I was doing teenth [short for sixteenth – about 1.75 grams] and two-gram hits maybe five times a day, that's quite a big habit. To pay for it you can deal or you can work. I've been lucky I've got skill behind me so I can earn good money quickly. If you buy by the ounce it's so much cheaper and you can go to work and earn your money without having to score, without having to put yourself at risk every day.

I got busted once for possession with intent to supply, I had a couple of ounces. They made it sound like I was Al Capone and I got five years' jail. When I came out I went to work as a mechanic for the Ministry of Defence. To my shame, I fucked that up well and truly because I got a habit again in five minutes.

Until about 15 years ago you couldn't really get help unless, it seemed to me, you were of a certain clique or social group. Got detoxed a couple of times but that's about it. About five or six years ago I went to a rehab, a Christian, "hallelujah" sort of place. They were paid by the social services and they also took my benefit. So they got more from me than from those that paid privately, but even so we were treated as second class and had to do all the work. It was rubbish. You got disillusioned. I still gave it a go, I really did, but I couldn't hack it. I ended up saying to them,"You call this Christianity?" and had a go at them and they decided I was a no-good communist git and a troublemaker.

I went back to heroin – it's very hard not to. I don't know how to stop now. I tried methadone, but I was using all the time as well because methadone's rubbish. So I enrolled at the clinic. The trial is different because I'm not trying to get better, I'm not trying to get a cure because I know that's probably out the window.

It's a completely different environment to the methadone clinic, there's less people and the staff remain practically the same so you can build up a rapport with them and a camaraderie with your fellow users, so it is a lot better.

You get a certain amount of satisfaction [from the diamorphine]. The feeling's not great but it fulfils its remit. I don't use anything else now, I'm quite good. I have a couple of beers, but not all that much really. I was initially on two 140mg injections of diamorphine a day and up to 100ml of methadone linctus, whereas now I am only injecting 80mg once a day but still take 80ml of linctus. The linctus keeps me well and the injection fulfils my need.

I do more with my life than I used to, but I would be happier if I could go to the clinic at 8am [the clinic opens at 10am], it would give me more scope to get a job. One person I know goes to work, but he's got a really understanding boss and works around clinic visits.

I spoke to Alan Johnson [former health secretary, who talked to users of the clinic on a visit to Brighton] and he said the trial had his backing. He intimated, without really saying, that if Tony Blair had still been in, things would be different. The prime minister would be better in the pulpit. He was a marvellous chancellor but he just doesn't have any people skills and he seems very narrow minded. The trial was already going before he came in so he's tied by ethical and medical restraints – you can't put somebody on something and take it away for no reason.

What would I say to people who say we shouldn't be giving heroin to heroin addicts? Well, it's ok for people to be against something that they know nothing about. They're just too narrow-minded to get it. And please, just don't get me started on the Conservatives.