A familiar face peers round the door and asks, "Does anyone need anything, I'm the waiter," before making an exit. A few minutes, and a quick briefing from his publicist later, he returns to the hotel room with a breezy, "It's great to be back in Berlin".

George Clooney, ever the joker, is actually in London, pausing briefly to spread the word about his new film, Syriana, on his way to the film festival in Germany.

The Hollywood star is much in demand with two loudly-applauded movies in circulation - Good Night, And Good Luck (which he directed, co-wrote and acts in) and Syriana (in which he appears). Both have had excellent reviews, awards and nominations lavished on them so that Clooney finds himself in contention for best director, best supporting actor and best picture at the Oscars next month.

Perhaps more importantly, both movies are classed as political films. Intelligent movies are so rare in mainstream US cinema that having two in cinemas at once adds up to a major event that requires Clooney to justify them.

He's never been shy and retiring when it comes to promoting his work, be it Batman And Robin, Ocean's Eleven or something more serious like Syriana. Clooney is that rarity in Hollywood: a genuine star who's open and honest, amusing and charming in interviews.

Settling down to chat, he admits there's a difference between interviews in the States and in this country. The US media is more interested in the celebrity aspects of storytelling as opposed to the story itself, he feels. "Usually, it's 'who are you dating?' - which I will answer later. So it's a different experience here even with celebrity-type films like Ocean's Eleven."

He had no particular agenda to make two political movies back-to-back, he was just interested in working on the stories. Good Night, And Good Luck raises issues of media responsibility by recalling the 1950s McCarthy Communist witchhunt in America through the senator's clashes with broadcaster Edward R Murrow. Syriana is much more potentially explosive, being a thriller involving corporate corruption, the oil business and terrorism.

The actor admits there have been a bunch of films of late, movies like The Constant Gardener, whose stories have had political underpinning. "The truth is ultimately there's a little bit of a coincidence," he says. "There's a social change in the States where people are interested in politics and political issues again, and films reflect that. I don't think it was a plan to slap them together, certainly it was an accident for me."

This isn't his first brush with controversy on screen. The 1998 Persian Gulf War drama, Three Kings, was more overtly political than either of his new movies. He tried and failed to get it re-released in 2002 during the lead-up to the Iraq war.

Some would prefer him to keep quiet. When he questioned the US government's action over that conflict, he found himself on a news magazine cover with the word TRAITOR splashed across his photograph.

Despite that, he has no worries about making political films again. "It wasn't going to get worse than it was at the time leading up to the war where anyone who had any questions was called unpatriotic or traitor," he says. "It's probably got as bad as it's got for anyone who has questions of authority, which is what our country is founded on. I don't think there's any great risk making these films.

"Also the climate changed after the Katrina incident. The press, for the first time in America, took this President to task. He had got by because he could stand around and say it was unpatriotic to go at the President at a time of war. Every other President has been held accountable and he has not. Katrina changed all that."

If Bush's public image has taken a bashing, Clooney's has remained intact. "Elements that existed in 2003 leading up to the war were much more toxic than they are now," he says. "I have been very careful not to stand up and say this is what you should believe, but these are the questions we should be allowed to ask.

"I can't demand freedom of the press and then say don't say bad things about me. I have to take my hits, I'm a grown-up. At the end of the day, I'm not afraid at all because, ultimately, we're a pretty good country at fixing our mistakes. And our mistakes are when we use fear to attack civil liberties. The one thing we have learned over our history is that authority unchecked corrupts."

His performance as a bearded, overweight CIA agent in Syriana has earned him good reviews and a Golden Globe award in advance of possible Bafta and Oscar acting prizes. The role was inspired by real life CIA officer Bob Baer. "The frustrating part was it was uncomfortable physically," he says. "I wasn't physically happy because I like to play basketball and have a normal life, and you're very isolated by what you're doing. I came late to the film. I finished Ocean's Eleven on August 1 and started Syriana on September 1. They'd already started shooting when I got there. It was like, 'go, you're working every day'." Hopefully, the praise being lavished on him makes the discomfort worthwhile. "It's nice when people are nice to you, and I've been on the other side of that," he says.

With both Syriana and Good Night, And Good Luck Oscar-nominated, he's competing against himself. So which Oscar would he like to win? "It's a tough call," he says.

He's proud to represent Bob Baer by playing a character who actually exists and has given great service to his country. He also enjoys being at functions with top directors Steven Spielberg and Ang Lee and have people ask his opinions.

All this talk of politics shouldn't be taken as evidence that Clooney means to run for office one day. The more cynical might say he's too honest and open to be a politician. He jokes that he'd "like to be a politician who gets laid".

More seriously, he rules out following the route of the likes of Reagan and Schwarzenegger. "One thing I don't want to do, and will not ever want, is politics. I don't have an interest in that, I do have an interest in political issues."

Growing up around a father who was a news broadcaster and a mother who ran for mayor means he's been around politics all his life. "It's something I've always been interested in. At a time like this in our country you have to pay attention," he adds.

He knows that people in his business are pigeonholed, realising equally there's nothing he can do about it. "I can't really define what people think of me. You try to function as you always have and let the chips fall where they may," he says.

"The interesting thing is this - every single day something is printed in the paper about me that has very little basis in truth. If you try to defend them all, you are a schmuck. So you have to pick your case, the one you want to argue."

Good Night, And Good Luck (PG) is showing in cinemas now. Syriana (15) opens on March 3.