Tony Blair and George Bush are "clinging to straws" to justify the war in Iraq, Hans Blix has said.
Mr Blix says the reality in Iraq was different from what had been 'spun'
The former UN chief arms inspector was writing in the Independent on Sunday following the release of the Iraq Survey Group's report on Wednesday.
The report found no evidence of weapons of mass destruction (WMD) but Mr Blair said it made clear Saddam Hussein had "every intention" of developing them.
Mr Blix writes the findings were more moderate than Mr Blair's interpretation
"Far from confirming Tony Blair's reported reading that Saddam 'had every intention of reviving his WMD programmes', the report suggests Saddam gave his officials the impression that he was interested in resuming programmes 'if sanctions were lifted'," he says.
"This is the new straw to which the governments concerned have begun to cling."
Mr Blix goes on to say that even if sanctions were lifted, the UN Security Council would have been unlikely to relax its ban on Iraq possessing WMD.
"Any 'breakout' by Saddam would have caused loud alarm bells to ring," he writes.
Mr Blix also points out that the Iraq Survey Group believed, as he does, that Saddam Hussein allowed the world to believe he still had WMD "to look bigger and more dangerous than he was".
"The inspectors appointed by the Bush administration to search Iraq for weapons of mass destruction have had to acknowledge that the reality on the ground was totally different from the virtual reality that had been spun," he writes.