Michael Howard's withdrawal from the Butler Inquiry is an act of opportunism

The Tory leader is an unconvcing contortionist. He supports the war but wants to make mischief as the doubts grow

Tony Blair cannot escape the consequences of his support for the war in Iraq. However hard he might try Michael Howard cannot do so either.

The Conservative leader has announced that his party will no longer be co-operating with Lord Butler's inquiry into the intelligence services. This would be a moment of considerable significance had Mr Howard opposed the war or even raised doubts about the Government's conduct in advance of the conflict. Instead the Conservative leader is an unconvincing contortionist. He supports the war, but wants to make mischief out of the conflict as doubts grow about its legality.

How tempted Mr Howard must be to raise the latest controversy when he faces Tony Blair at Prime Minister's Question Time tomorrow. After all, an unlikely quartet has prepared the ground for him. The former Prime Minister, John Major, has called for Mr Blair to publish the Attorney General's full advice on the legality of the conflict against Iraq. So has the former Foreign Secretary Douglas Hurd. Tony Blair's old ministerial colleagues, Robin Cook and Clare Short, have made similar demands. This is quite a warm-up act

Mr Howard seeks to be the star turn, but withdrawing from the Butler inquiry does not get him very far. The Prime Minister has a convincing, ready-made response to Mr Howard's questions relating to the war. It goes along these lines: "Neither the current leader of the opposition nor his predecessor questioned the legal basis at the time the war took place. They were at least as keen as the government for the war to commence. The right honourable gentleman is an opportunist". Mr Howard has no answer to that. He is being opportunistic.

The original support of the Conservative leadership for the war makes the current political situation in Britain much less febrile than it appears on the surface. At its most basic it means that the main opposition party, the only alternative government, cannot benefit politically from the chaotic aftermath of the conflict. Their leading figures are unconvincing when they huff and puff over specific issues. Lord Butler might be feeling a little lonelier this morning, but most voters will not be convinced by the Conservatives' absence from his review.

As Mr Major and others suggested at the weekend there are thorny, potentially embarrassing questions relating to the legality of the conflict. UN resolution 1441, much quoted by ministers as legitimising war, was deftly drafted so that its precise meaning was vague. The resolution called on Saddam to co-operate fully with the UN inspectors or "face the consequences".

Those consequences were not specified as the countries involved could not agree on what they were. Resolution 1441 was a preliminary one that implied the need for a more precise follow up before war. Mr Blair did not get a second resolution. There must be a suspicion that there were some embarrassing qualifications in the Attorney General's broader, unpublished legal assessment.

Mr Howard is the last person in British politics able to raise such a suspicion. Not for the first time he is hindered by his own enthusiasm for the conflict.

Mr Blair made many calculations in the build up to war, but I suspect the support of the Conservatives was a key and underestimated factor. Indeed it is quite possible that Mr Blair would not have dared to back President Bush in the first place if the Conservatives had been opposed to war. Mr Blair became a Labour MP in the 1980s when the Conservatives won landslide elections. As a result he is conditioned to take the Conservatives seriously, neurotically alert to any political situation that might aid their recovery. Fighting a controversial war that the Tories had opposed would have been such a situation.

One of the reasons why Mr Blair has been so timid over the euro is the Conservatives' opposition. If Mr Blair were to lose a referendum on the single currency, the Conservatives would be the main beneficiaries. Indeed one of the most pro-European ministers in the government tells me Britain will never join the euro while the Conservatives are opposed. As far as the war is concerned Mr Blair knew he would have the support of the Tories. In the broadest electoral sense he had nothing to lose. He will not lose very much by Mr Howard's opportunistic withdrawal from the Butler inquiry.

Some senior shadow cabinet members insist that they had no choice but to back the war last year. Any other course would have laid them open to even graver charges of cynical opportunism. But there were two credible options for the Tories in advance of the conflict. One would have been to support the war in principle, but to raise far more critical questions and to make their support conditional on those questions being addressed. Messrs Major, Hurd, Rifkind and Heseltine all expressed concerns in advance without being unequivocally opposed.

The other would have been to accept the powerful arguments of Ken Clarke who opposed the war largely on the highly responsible grounds that it would increase the risk of terrorism at a time when Iraq had ceased to be a great threat. If Mr Clarke had led the Tories in the build up to the war they would be claiming triumphant vindication now. Their refusal to co-operate with the narrowly defined Butler inquiry would have been merely another nail in Mr Blair's political coffin.

Instead Mr Blair faces no opponent capable of dealing a killer blow. Clare Short makes the front pages, but she cannot win a general election. This is also the case with Charles Kennedy, even if, unlike Ms Short, he is a member of a different political party. Wisely Mr Kennedy does not even pretend that his party can form an overall majority at the next election. The Liberal Democrats will probably perform well in this summer's elections, partly as a result of their opposition to the war, and more than creditably at the next general election. But they will not form the next government. Only the Conservatives are in a position to oust Mr Blair, but they backed him on the issue that has overwhelmed his second term.

However much Mr Howard manoeuvres over the next few months the original unswerving support of the Conservatives for the war means that the conflict will not be a great issue at the next general election. In the election campaign Labour's dissenters will rally round. Ms Short and Robin Cook will be out on the campaign trail on behalf of Mr Blair. The Conservatives will be in no position to woo the opponents of war and therefore have no motive to raise the issue. The Liberal Democrats will make an attempt, but the third smaller party cannot dictate the terms of an election campaign.

Oddly Mr Blair will get his desire to 'move on' from the war when the next general election moves into view. An election should be a period when scrutiny over major issues becomes even more intense, but that depends on the other main party having an alternative policy. Refusing to co-operate with the Butler inquiry while supporting the war does not amount to an alternative policy.

s.richards@independent.co.uk