Prime Minister Tony Blair today launched a passionate defence of the war in Iraq, saying that September 11 came as a ''revelation'' to him and persuaded him of the need to act against rogue states.

Mr Blair openly acknowledged that his decision to go to war was the most divisive he had ever made, conceding ''it remains deeply divisive today''.

In a speech in his Sedgefield constituency the Prime Minister went on: ''The nature of this issue over Iraq, stirring such bitter emotions as it does, can't just be swept away as ill-fitting the preoccupations of the man and woman on the street.'' That was because the nature of the ''global threat we face in Britain and round the world is real and existential and it is the task of leadership to expose it and fight it, whatever the political cost''.

Mr Blair, in a detailed defence of the case for war against Saddam Hussein's regime, said: ''No decision I have ever made in politics has been as divisive as the decision to go to war in Iraq. It remains deeply divisive today.

''I know a large part of the public want to move on. Rightly they say the Government should concentrate on the issues that elected us in 1997: the economy, jobs, living standards, health, education, crime.

''I share that view and we are.''

But the premier said the issue of the conflict had to be tackled head-on.

He said there had been three inquiries into the conflict, including the Hutton report, and none had shown any Government attempt to falsify intelligence in relation to Iraq.

And the Prime Minister said he had mentioned the now notorious 45-minute claim about the readiness of Saddam's weapons only once in his statement to MPs and had not mentioned it again in any debate.

Mr Blair said he had never insisted Saddam was an imminent threat to the UK and read extracts from his own speeches to back his claim. He went on: ''The truth is, we went to war to enforce compliance with United Nations resolutions.''

And he added: ''Had we believed Iraq was an imminent direct threat to Britain, we would have taken action in September 2002. We would not have gone to the UN. Instead, we spent October and November in the UN negotiating UN resolution 1441. We then spent almost four months trying to implement it.''