Blair insists Iraqi weapons exist and will be found.

(From Agence France Presse)

British Prime Minister Tony Blair staked his political credibility on finding weapons of mass destruction in Iraq, admitting it would damage the case for war if none were uncovered but insisting this was inconceivable.

Blair -- whose current trip to Iraq, Poland and Russia has been dogged by the issue -- warned his critics they would have to be patient, also hinting that evidence existed which had yet to be made public.

"What I have said to people is, over the coming weeks and months we will assemble this evidence and then we will give it to people," Blair told Sky News in Saint Petersburg, where he is attending a celebration of the city's 300th anniversary.

"And I have absolutely no doubt whatever that the evidence of Iraqi weapons of mass destruction will be there," he said in an interview with the British television channel.

Blair conceded that the case for war -- which was based around ousted Iraqi leader Saddam Hussein possessing illegal chemical and biological weapons ready for immediate use -- would be dented if nothing was uncovered.

"Of course it would matter, and that's why it's important that we carry out this task," he said.