Former UN weapons inspector Hans Blix warned Washington and London in the weeks before the 2003 invasion of Iraq that he was growing less confident in evidence Iraq had banned weapons, he said on Tuesday.

Blix was the latest senior figure to give testimony to a British inquiry on the Iraq war that has raised difficult questions about the decision by US President George W Bush and British Prime Minister Tony Blair to invade.

The United States and Britain justified the invasion by arguing that Iraqi dictator Saddam Hussein had chemical, biological and nuclear weapons programmes and needed to be disarmed, although after the war no banned weapons were found.

Blix, who has long been an outspoken opponent of the decision to invade, told the British inquiry Washington was 'high' on military power, and the US military timetable was 'out of sync' with the diplomatic timetable, which would have given his team more time to carry out inspections.

Blix headed a UN team searching for banned arms, known as weapons of mass destruction (WMDs) in Iraq. He said his group's failure to find any WMDs should have caused Washington and London to question their intelligence.

'I talked to Prime Minister Blair on February 20, 2003 and then I said I still thought that there were prohibited times in Iraq but at the same time our belief in the intelligence had been weakened,' Blix told the inquiry.

'I said the same thing to Condoleezza Rice .... I certainly gave some warning that things had changed,' Blix said, referring to the former US Secretary of State.

The United States and Britain had both published intelligence reports in the lead-up to the war which they said showed Iraq had WMDs or the capability to make them.

Blix's comments added weight to negative appraisals of the invasion given by other senior figures at the inquiry. The war led to the overthrow and execution of Saddam and unleashed years of bloody sectarian strife which almost tore Iraq apart.

Blix had criticised Iraq before the invasion for not being transparent about its weapons programmes, but his reports fell short of giving Bush and Blair compelling evidence to secure UN support for war.

The United States and Britain tried to persuade the UN Security Council to endorse their decision to invade Iraq, but when the council failed to pass a new resolution, they invaded anyway, arguing earlier resolutions justified the assault.

'When she said that the military action was simply upholding the authority of the (UN) Security Council, it strikes me as totally absurd,' Blix said, referring to Rice.

Blair's successor Gordon Brown set up an inquiry last year, chaired by former civil servant John Chilcot, to learn lessons from the war. Blair and Brown's Labour Party, in power since 1997, was defeated in an election in May this year.

The former head of Britain's domestic intelligence agency told the inquiry last week there had been only a low risk of an Iraq-backed attack on Britain before the war, but that the country was 'swamped' by terror threats after the invasion because the conflict had radicalised some Muslims.

Blair has come in for criticism for committing Britain to the invasion, which was unpopular with the British public, including among leading figures within his left-leaning Labour Party. British troops have since withdrawn.

The inquiry is expected to conclude at the end of this year. Previous probes have cleared the government of any wrongdoing.-Reuters