A play mocking US President George Bush as a pyjama-wearing dimwit has been such a success that it is extending its run at a larger London theatre.

The Madness of George Dubya mercilessly satirises Mr Bush and British Prime Minister Tony Blair on their approaches to war in Iraq.

The play, now at the Pleasance Theatre in Islington, north London, sees Mr Bush locked in a bunker, which he calls a "bunkbed", while his military advisers plot a nuclear strike against Saddam Hussein.

I don't think, like many of us, that the reasons we have been given for going to war are the honest reasons Dustin Hoffman

"As war comes closer, the mood among audiences has changed," said actor Nicholas Burns, who plays Mr Blair.

"The audience is actually laughing more, but the tension behind their laughs has grown. People are scared."

The show's success comes as Oscar-winning actor Dustin Hoffman joined a growing wave of celebrities who have attacking Mr Bush's policy on Iraq.

He told the audience at London's Empire Awards ceremony the US president was "manipulating the grief of the country" after the events of 11 September 2001.

President George Bush is satirised as a buffoon in the play

"I don't think, like many of us, that the reasons we have been given for going to war are the honest reasons," he said.

"I believe - though I may wrong because I am no expert - that this war is about what most wars are about: hegemony, money, power and oil."

Debate

Hollywood actor George Clooney has also spoken out about the impending war, calling for further debate on the issue.

Promoting his directorial debut Confessions of a Dangerous Mind, he also urged film-makers not to shy away from difficult and intelligent subjects, including a possible invasion.

"I'm concerned that in the United States we are not embracing what we normally do, which is have a debate on the subject," said the Ocean's Eleven star.

"I hope that we will continue to raise the level and have people ask the tough questions."

Stars including Sean Penn, Martin Sheen and Susan Sarandon have already voiced their fears about the consequences of war.

George Clooney has added his voice to a growing list of anti-war celebrities

US poet laureate Billy Collins has called for political protest if needed and defended anti-war poets who caused a symposium at the White House to be cancelled.

'Not racist'

"I have tried to keep the West Wing and the East Wing of the White House as separate as possible because I support what Mrs Bush has done for the causes of literacy and reading.

"But as this country is being pushed into a violent confrontation, I find it increasingly difficult to maintain that separation," said Mr Collins.

The UK's poet laureate Andrew Motion recently penned an anti-war poem which suggested that Mr Bush was trying to follow in his father's footsteps by embarking on a war.

The Madness of George Dubya was written and directed by Justin Butcher, who wrote the script in three days and rehearsed it for in six days.

"This is not a racist, anti-American thing. It's a satirical attack on what the US and British governments are doing," he said.

The play has transferred from the fringe Theatro Technis in Camden to the larger Pleasance venue, and will run until 23 February.