Amid an increasingly bitter political row the Tories have defended their decision to withdraw support from the Butler inquiry.

Following Labour and Liberal Democrat charges of "opportunism" the shadow foreign secretary defended Michael Howard's decision.

Speaking on the BBC's Today programme Michael Ancram said: "It is quite clear now they are looking at the structures, systems and processes as the priority, as Lord Butler himself said, focus principally on them, rather than on the judgments made by individuals.

"That type of inquiry is not going to satisfy the doubts that exist in the public mind about the way in which the government handled the intelligence in the run-up to war."

Decision slammed

But both Labour and the Lib Dems have condemned the Conservatives' decision to withdraw support from Lord Butler's inquiry.

Trade secretary Patricia Hewitt said Howard had proved his "dreadful reputation for opportunism".

And Lib Dem leader Charles Kennedy said the Tories had committed a political u-turn of enormous proportions.

"The position of the Conservative Party, quite frankly, is risible," he said.

Kennedy said Howard had been happy to join the inquiry - and repeated his personal opposition to its terms of reference.

"It will not answer the fundamental question which is the one which the British people increasingly want addressed," he said.

Critics also point to reports that Michael Mates, the Tory representative on the inquiry, has refused to resign from it.

Mates is said to be angry at Howard's failure to consult with him before withdrawing his support.

The attacks came less than 24 hours after Howard wrote to the prime minister announcing his decision to reject the application of the inquiry's remit.

Letter

The Tory leader said a document released by the Butler committee stressed its review would focus on structures, systems and processes. 

"It does not include amongst its aims an examination of the acts or omissions of individuals," wrote Howard.

"It makes clear that it will consider such acts or omissions only in the context of its examination of structures, systems and processes. 

"There is no basis in the terms of reference for that view and I consider it a quite unjustifiable restriction on the Committee’s approach.

"After careful reflection of these matters, I have, therefore, decided with regret to withdraw my co-operation from the Butler review."