It's the night before the morning after, when he's expected to pick up his eighth Oscar nomination for his performance as a famous actor on his last legs who becomes infatuated with feisty young Jodie Whittaker. O'Toole doesn't do coyness. It clearly hurts that, like Martin Scorsese, he's one of the most nominated people never to win an Oscar. "Of course it matters to an actor to be nominated, " he says, "but it means bugger all if you don't win."

His actress daughter Kate and 23-year-old son Lorcan, whom he brought up after a custody battle with American model Karen Brown, are somewhere around. "I go to Kate's place in Connemara lots of times, " he tells me. "Did you know she's been writing a column in the Clare Champion? Kate's Corner it's called. She's written some nice pieces."

O'Toole's nomination the next day brings general delight. Of his four rivals for best actor at next month's awards, only Forest Whitaker was even born the first time O'Toole sat through the agonising ceremony in Los Angeles. Now it is Whitaker, playing Idi Amin in The Last King of Scotland, who is likely to prove his strongest competition, although Leonardo DiCaprio is winning plaudits for Blood Diamond.

In fairness, even O'Toole could scarcely claim that his performance in Venus required as much preparation as, say, his performances as TE Lawrence in David Lean's masterpiece Lawrence of Arabia, the film that made him a star in 1962 - or King Henry II in Becket in 1964 and in The Lion in Winter in 1968.

In Venus, O'Toole plays an ageing actor with an eye for the ladies who forms a curious but touching friendship with a considerably younger woman. As the American television interviewer Harry Smith put it to O'Toole last week: "Now, when you were reading the part and you could see that was a lecherous old man, did you think: 'Now, this is going to be a stretch for me?'" "Oh dear, oh dear. Not exactly, " the star replied with a smile. O'Toole himself put his young co-star Jodie Whittaker to rights when she described the film as "a kind of love story". Peter apparently butted in and said: "It's not a love story. You're a little chav and I'm a dirty old man - that's basically what it's all about."

Which is not to say that he does not deserve to win.

Some of his most cracking performances owe not a little to the intrigue of where art ends and real-life begins. Think Jeffrey Bernard is Unwell on the London stage and My Favourite Year in 1982 when, it could be argued, a drunk actor won an Oscar nomination for playing a drunk actor, albeit brilliantly.

So it has been with Venus. There is no doubting that the material could have left a nasty taste in the mouth. Nobody likes a dirty old man. Yet O'Toole is almost heartbreaking at conveying a frail if spirited old man captivated by the charms of youth. An Oscar at last would be a marvellous achievement for the son of an Irish bookie and a Scottish nurse who grew up in Leeds, now in his 75th year.

Stomach cancer and diabetes have forced modifications in his behaviour, but Leslie Phillips, the British comic actor who co-stars in Venus, says O'Toole is still keen on getting his own way. "He's a strong man; he's a man who won't tolerate fools. He's very unpredictable. He's got older and got bags of guts and goes for it. He's also got a tremendous quality of humour."

And he's a trouper. Halfway through filming Venus, O'Toole fell and broke his hip. "We all thought the film was finished. They couldn't fix it. They couldn't screw it in, his bones were so brittle, " Phillips recalls.

But after a complete hip replacement, O'Toole pluckily returned to the set and partied until late at Tuesday night's premiere.

"I hope he wins, " says Phillips.