Tony Blair is to face a "trial" in April over his decision to go to war with Iraq in a new play.

Called To Account will be based on real testimony from key witnesses involved in the run-up to the controversial war.

It is the latest "Tribunal play" from the Tricycle Theatre that last month won a special Evening Standard Theatre Award for its pioneering work in political theatre.

Lawyers Phillipe Sands QC and Julian Knowles will begin interviewing ex-Cabinet ministers, MPs, civil servants, intelligent experts, ambassadors and journalists this month.

Their testimony will then be edited into a two-hour play by Richard-Norton Taylor, the writer whose previous plays Justifying War: Scenes from the Hutton Inquiry, Half the Picture - based on the arms to Iraq inquiry - and The Colour of Justice based on the Macpherson inquiry into the police investigation of the murder of Stephen Lawrence, were all performed to critical acclaim at the Kilburn-based theatre.

It is expected that audiences will vote before and after the performance on whether the Prime Minister is guilty of violating international law in joining the United States in the 2003 invasion of Iraq.

In an ironic twist Mr Sands and Mr Knowles will question some of the 20 witnesses in Matrix Chambers where the Prime Minister's wife Cherie Blair practises as a barrister. Mrs Blair was informed of the Tricycle's play on Friday.

The evidence will be recounted in the play by actors although Mr Blair will not be portrayed onstage.

Tricycle director Nicolas Kent said: "A lot of people feel that their views have never been debated. There is a mood in the country that we don't want to be sucked into future wars without a debate. The only way to ensure that happens is to investigate why we went to war.

"But it isn't a trial, it is an indictment. We are looking at whether there is a case for the Prime Minister to have taken the UK to war."

But Mr Kent added that although his personal view was that "Blair was railroaded by Bush into the war", the play would be balanced.

Like the Tricycle's Guantanamo and The Colour of Justice, it is anticipated that Called To Account will transfer to the West End following its monthlong run which begins on 19 April.

Channel 4 is set to air its own programme based on an imaginary trial of the Prime Minister. The Trial of Tony Blair, starring Robert Lindsay as the PM, imagines him being put on trial for war crimes after he leaves power.

The play - written by Alistair Beaton, author of the critically acclaimed A Very Social Secretary about David Blunkett's fall from grace - will be on More4 next Monday.