Liam Neeson's fascinating portrayal of pioneering sexologist Alfred Kinsey was passed over by the Academy Awards. But the actor takes the snub in his stride, he assures Michael Dwyer - and, with projects by Ridley Scott, Neil Jordan and Steven Spielberg in the pipeline, who needs the Oscars?

There was such strong competition for a place in the best actor category for last Sunday's Oscars that an alternative quintet of nominees, which would have been just as respectable, could have included Paul Giamatti (Sideways), Javier Bardem (The Sea Inside), Kevin Bacon (The Woodsman), Jeff Bridges (The Door in the Floor) and Liam Neeson (Kinsey).

Neeson, who had been hotly tipped for a nomination, was philosophical about his omission when we met in London recently. "You know what I am pissed off at? I wasn't holding out great hopes for myself, but I would have bet anything that Bill Condon would have got a nomination for his screenplay. I was amazed that he didn't."

Working from director Condon's incisive screenplay, Neeson draws a fascinating portrait of Alfred Kinsey, the pioneering scientist who, in 1948, shocked the American public with his book, Sexual Behaviour in the Human Male. It drew on interviews with thousands of subjects about the most intimate details of their lives, and lifted the cloak of secrecy and guilt from a society that dared not speak of such private practices.

Does Neeson believe the film was the victim of a conservative backlash in the US? "That's been said to me. I just don't want to sound like it is sour grapes on my part, but there have been these groups campaigning against the film. I personally encountered one group back when we were shooting it.

"We were in New Jersey one day and there was an incident on the set. This flier had been sent around and it claimed all sorts of things about Kinsey - that he collaborated with paedophiles, that he was a pervert, and so on. The flier told people to attend a rally on the street where we were shooting the film the next day. We all felt some trepidation the next morning, but only five elderly people turned up. They were walking around with placards and we ended up giving them lunch that day."

Neeson agrees that there are timely parallels between the paranoid era of the Cold War, when Kinsey's findings were published, and present-day America, with its reassertion of conservative values and the climate of fear post-September 11th.

"Do you know that sex researchers have had to go underground in America?" he asks. "There was an exposé about this in the New York Times a few weeks ago, and it was just riveting reading. These top universities now have to use coded messages to relay information about sexual research. It's very worrying.

"Then there is the campaign to promote total sexual abstinence programmes among teenagers and the federal government is funding these clubs and associations. They are downplaying the importance of condoms and passing on total misinformation, even though Aids and HIV are still very big problems in the US."

Neeson resides in upstate New York with his actress wife, Natasha Richardson, and their young sons, Michael and Daniel. "I live in a blue state, but I have definitely seen changes," he says. "You have to look over your shoulder, especially since 9/11. I wasn't there at the time, but my wife was and my kids were at school that day. The shock really hit New York and the city hasn't come out of it yet. There is a sense of fear and uncertainty in the city now that never was there before. The energy has been sapped out of the place. The country has had to grow up very quickly in the last four years."

He insists that the film does not portray Kinsey as a saintly character. "It presents him as a complex and tenacious man with great willpower and the kind of obsessive quality we find in many people who ultimately change society. It was hard work, but I like hard work."

It was made easier, he says, because he was working with former colleagues. Laura Linney, who plays Kinsey's wife, Clara, co-starred with him in the 2002 Broadway revival of The Crucible, and they were in the movie Love, Actually a year later.

"We have this really nice routine when we work together," he says. "Each of us understands how the other works, so it's quite an intuitive experience. She's a good friend, too."

Clyde Martin, the researcher who introduces Kinsey to gay sex, is played by Peter Sarsgaard, who was in Neeson's 2002 submarine drama, K-19: The Widowmaker. As it happened, the other recent controversial male-male screen kiss involved another Irish actor, Colin Farrell in Alexander, and Neeson is amused by the coincidence.

"I've met Colin a couple of times," he says. "In fact, at one stage, I was going to be playing his dad in Alexander. That was the first time I met him and he was with Oliver Stone at a hotel in New York. I've met Colin a few times since. He's a really nice guy and there's a side to him that doesn't take it all seriously. But he's also a very, very good actor. I thought he was exceptional in Phone Booth. He had to carry the whole film."

Unlike Farrell, who was catapulted into starring roles by his mid-20s, Neeson, who is now 52, had to work his way up through supporting roles and independent productions after making his film debut as Gawain in John Boorman's Excalibur, which was shot in Ireland 25 years ago.

"Wow! 25 years! Now there's an excuse for a drink. A lot of water has gone under the bridge in those 25 years - a few rivers. It certainly doesn't feel like it's been that long. It's funny, but I ran into Helen Mirren recently with her husband, Taylor Hackford, and he's doing so well now with Ray."

Back in 1981, when they were making Excalibur, Neeson, Mirren and many others from the film's cast and crew were regulars at Sheehan's bar off Grafton Street in Dublin. "That's where we got our cheques cashed," Neeson recalls. "It's funny, but every time I go over to Dublin, I call in to see Dermot at the bar, but I always seem to miss him. Of course, it's a wine bar now - totally different from the days when we were making Excalibur.

"Dublin has changed so much, and not for the better, I think. There's a ruthlessness to the city now that wasn't there before. I was in Dublin a few months ago, when we were shooting Breakfast on Pluto, and if I saw one kid throwing up on the street, I must have seen a hundred of them. I was just shocked at the number of kids I saw going around drunk."

Neeson spent a week in Dublin and another in Kilkenny filming Breakfast on Pluto, which reunites him with Neil Jordan, his director on Michael Collins. "It's even hard to believe that it's now 10 years since we made Michael Collins," he says. "It was lovely to be working with Neil again, and it was like a Michael Collins reunion with myself, Stephen Rea and Brendan Gleeson all together in another film. A great bunch of guys. All we were missing were Aidan Quinn and Julia Roberts.

"I must say, Neil's cinematic language has increased twentyfold in the 10 years since we did Michael Collins. We had a small budget for Breakfast on Pluto, but Neil just went for it. Everyone else was racing after him just to keep up with him. He was pretty extraordinary and always coming up with imaginative ideas for doing scenes different ways. He was firing on all pistons every day, six days a week."

In Breakfast on Pluto, Jordan's second Patrick McCabe adaptation after The Butcher Boy, Neeson plays a priest who unintentionally fathers a child with his housekeeper (played by Eva Birthistle). Their son (Cillian Murphy) grows up a transvestite with ambitions of becoming a supermodel in London.

When I mention I had seen a promo reel for the film and that Murphy in full drag looks like a particularly beautiful Spanish actress, Neeson laughs and says: "He does look amazing. Almodóvar will be after him big time! And he's a very good actor, too."

Neeson and Murphy are both in Christopher Nolan's Batman Begins, which opens here in June, but they don't have any scenes together. "Cillian plays a villain, The Scarecrow, and I play this upstanding chap called Henri Ducard, the mentor to the young Mr Wayne. That was a great gig - two weeks on, then a week off, a week on and maybe three weeks off. Chris Nolan is a real talent and so laconic. There's absolutely no pressure on the set with him, even on a film of this scale. Very few directors are so at ease on a set. And he's never away behind a bank of monitors, whereas some directors seem to be half a mile away."

The conversation turns to Christian Bale, who plays the dual role of the young Bruce Wayne and Batman in that movie, and to how much weight Bale lost to play the lead in the dark thriller, The Machinist, which opens here in a fortnight.

"I don't understand what all that is about," says Neeson, shaking his head. "I dropped about 10 pounds for Kinsey, because I wanted that frailer look. And then there was the hairstyle - it was described in one biography of Kinsey as being like a wheat field blowing in the wind. They also designed very subtle fat suits for Laura and me as we grew older in the film."

Before Batman Begins and Breakfast on Pluto are released here, Neeson will also be seen in Ridley Scott's lavish historical epic Kingdom of Heaven, which is due in May. "I play Godfrey of Ibelin, Ibdelin being this area outside Jerusalem," he says. "He's a Crusader and a general who comes to Spain to find his bastard son, who's a blacksmith in Jerusalem and is played by Orlando Bloom. There's a lot of action in it and it looks terrific, as you'd expect from Ridley Scott. And Brendan Gleeson is in it, too, but all my scenes were shot in Spain, whereas Brendan was in it after they moved to Morocco. Brendan and I keep waving to each other at airports!"

Neeson met his wife Natasha Richardson when they acted together in Eugene O'Neill's Anna Christie on Broadway in 1993; both of them had separate stage projects planned for this year. "She's playing Blanche in A Streetcar Named Desire on Broadway, so she's going into rehearsals now. I was going to do A Touch of the Poet this fall, but that's not going to work out, so maybe next year. I've been approached by Steven Spielberg to play Abraham Lincoln. In fact, there's a really interesting book on Lincoln by Clarence Tripp, who was one of Kinsey's acolytes. It's a fascinating read."

Kinsey opens today