It follows that the Prime Minister could argue that the way in which he secretly gave his word to President George Bush in April 2002 that he would support him in an attack on Iraq was within his power. And the way the legal advice was manipulated, the risks of weapons of mass destruction exaggerated, and the position of France misreported, was legitimate as a way for the Prime Minister to keep the public on-side for a decision he had already made.
It is for the Prime Minister and him alone to decide whether there is to be war. His efforts to keep Parliament and public opinion on side became a presentational and not a democratic or legal requirement.
It is because these arrangements are profoundly undemocratic and because this personalised power leads to ill-considered decisions, that I am introducing the Armed Forces (Parliamentary Approval for Participation in Armed Conflict) Bill. It lays down that the Government must seek the approval of both Houses of Parliament for the deployment of the armed forces in conflict or for a declaration of war.
The Bill proposes two ways approval could be given. The first is that the Prime Minister would lay before each house a report setting out the reasons for participation; the legal authority for doing so; and any appropriate information on the likely extent and duration of the conflict and which forces will be involved. The Bill also provides that if the need for action is urgent, retrospective approval can be sought and requires the Prime Minister to lay a report before each House as soon as is practicable. Should approval be withheld, the participation of our forces for more than 30 days would be illegal.
The Bill was drawn up as part of the Select Committee on Public Administration's report on the Royal Prerogative of 4 March 2004. It is supported by Charter 88 as part of its campaign to improve democracy. It is also sponsored by MPs of all parties, including Ken Clarke, William Hague, Menzies Campbell and Alex Salmond; 200 MPs have signed a motion supporting the principle.
In opposition, Labour made clear that the Royal Prerogative would have to be modified in relation to making treaties and going to war. But Jack Straw wrote in 1994: "The Royal Prerogative has no place in a modern democracy." Gordon Brown and Stephen Byers have said since the start of the Iraq war that Parliament and not the Prime Minister should make the final decision about whether the country goes to war. But sadly the Government is opposing the Bill.
The Butler report shows how this concentration of power in one person leads to informal and ill-considered decisions. It also shows how little the Cabinet knew and how the Attorney General's full advice was not shared with the Cabinet, let alone Parliament.
The Government argues that there is no need for such a law because the Prime Minister allowed MPs a vote on 18 March 2003. But our troops were on the ground and there was an huge exercise to prevent the Prime Minister being humiliated by the size of the rebellion.
There is no guaranteethat bad decisions would not be made but the democratic scrutiny would strengthen the influence of public opinion and lead to more thoroughly considered decisions.