David Hockney, I had been instructed, will only wish to talk about Robert Mapplethorpe. But, it transpired, this must have been wishful thinking on the part of the gallery owner. For although the English artist has curated a show of the American artist's photographs, 15 or so years after the latter's death in 1989, there is only one subject which really fires Hockney up when we meet in London: smoking.

He is passionately pro-fags (perhaps even more in the English than the American sense of the word); almost obsessively so. I admit to being partly to blame for opening up the subject, sharing many of his views on smoking. The problem is particularly acute in Los Angeles, the flaxen-haired Yorkshireman's adopted home for the past three decades where it's considered almost more of a crime to light up a cigarette than to shoot someone down.

The anti-smoking lobby is "quite tyrannical, people should be appalled really... if you go to New York everybody's on Prozac and drinking water. The pharmaceutical companies are taking over. That's what replaces cigarettes: pharmaceuticals. It's a fraud. Nobody's saying anything and they think they can just get away with it. Well, it's a great pleasure - smoking - and they've got to be realistic that there's going to be a hard core for ever," he says, sounding very put-upon and Alan Bennett-ish.

"The choice is not between smoking and immortality; you're gonna die anyway. It's absurd," he continues. "Do you know the poem: 'Give me a doctor, partridge-plump/short in the leg and broad in the rump/an endomorph with gentle hands/who'll never make absurd demands/that I abandon all my vices/nor pull a face in a crisis/but with a twinkle in his eye/will tell me that I have to die'?"

I have to confess that I'm not familiar with the poem - Hockney doesn't know who wrote it although he suspects it might be Auden - but think it splendid both in its sentiment and its rendition. He used to read a great deal of poetry and memorise it: "Well, if something tickles you, then you read it again and you remember it, don't you?" But as he retreats further into the deafness which runs in his family and first afflicted him many years ago, poetry has been abandoned along with music - one of his other great loves.

"I have difficulty with a lot of poetry now because I don't know enough about pop music, and I sometimes think there are a lot of references I'm not getting because I'm assuming that the folks writing it are younger than me... and so... I'm too deaf really to listen to music or the radio or television," he says. "And what people never understand about people who are going deaf is that it isn't

the silence that's the problem, it's that it's a very confused sound. It's such hard work that you give up when you're out, and think, 'OK, I'm going home now.' I'm always the first to leave. I've got to a point in life where I need to accept it. I'm unsocial because you have to be. Art openings, for instance, are the worst for me. I won't go. And

it will always be that way because there's nothing you can do

about it, actually."

This is delivered in a tone more of sorrowful resignation than anger, which is reserved for another subject - and so, pretty soon, we're back to nicotine. One of the reasons why many of my questions, however seemingly unconnected, lead Hockney to the same response is that smoking - the lack of debate, the increasing restrictions - has become a metaphor for him of so many modern-day ills. There was a time when he used to rail against the up-tightness and illiberalism of England. But now, for someone who chose to

live in the Sunshine State because of its wide, open spaces and the attitudes that landscape reflected, he must find himself fenced in

by the bossy health police, and the fearful vigilance against