Tony Blair has admitted that biological and chemical weapons, which he once insisted Saddam Hussein had primed for use, may never be found.

In testimony to a committee of senior MPs yesterday, the prime minister also insisted he had exerted real influence over Washington's approach to post-war Iraq and defended to the hilt his close ties with President George W. Bush.

"We know Saddam Hussein had weapons of mass destruction but we know we haven't found them," Blair said. "I have to accept we have not found them, that we may not find them."

Blair persuaded reluctant MPs to back war on Iraq last year on the basis that Baghdad had banned weapons and could use them at any time.

A now notorious dossier, released in September 2002, said some of

them could have been let loose within 45 minutes of an order to do so.

Yet more than a year after Saddam was toppled, no such weapons have been found. Blair's public trust ratings have withered over the same period.

Blair said the absence of banned weapons did not mean Saddam posed no threat to the region and to world stability, and that he was glad he had been deposed.

"They could have been removed, they could have been hidden, they could have been destroyed," he said. "The truth is, he was a threat."

Many in the Labour Party have not forgiven him for the war and his "shoulder-to-shoulder" stance with President George W. Bush since the September 11 attacks on the United States.

Critics claim the premier has secured little in return.

"I can see particularly within my own political family, it's a problem

sometimes," Blair said, but refused to give up London's closeness with Washington despite disagreements over issues like climate change.

He said full transfer of sovereignty to an Iraqi government, and an emphasis on building up domestic forces rather than pouring in more foreign troops, was a British blueprint.

"If you look at what has happened in Iraq recently ... I think we have had a very great deal of influence," he said.

Usually collected, the premier was riled by persistent questioning about any gains he had secured by consistently supporting Bush, often at the expense of European allies.

"We have a good relationship, believe it or not, with France and Germany but I am not going to have the relationship with the United States of America subordinated to the interests of any other country," Blair said.