"I did not authorise the leaking of the name of David Kelly," Blair told reporters on his flight from Shanghai to Hong Kong, the last stop in his East Asia tour.

"The important thing is to let the inquiry do its work," Blair said referring to a judicial investigation the government has called into the suicide of the former UN arms inspector at the centre of allegations that Downing Street exaggerated the threat of Iraq's weapons of mass destruction.

The issue of how Kelly's name came to be put in the public domain is likely to be central to the investigation into the scientist's apparent suicide, led by Lord Brian Hutton.

"I believe we have acted properly throughout. There are a whole lot of questions that the inquiry will ask and we will answer them," Blair said.

His comments came as pressure mounted on his Defence Secretary Geoff Hoon over his role in the affair.

The controversy has seen Blair's popularity plunge in the opinion polls and left him fending off calls for his resignation as he grapples with his biggest crisis since coming to power in 1997.

In an indication of how damaging the controversy has been for Blair, an ICM survey found that 54 percent of British voters are unhappy with his performance as prime minister.

The poll, published in the left-wing Guardian newspaper Tuesday, found just 37 percent of respondents to be happy with Blair, giving the prime minister an overall approval rating of minus 17.

In the immediate aftermath of successes in the Iraq war, launched in March, Blair rode high on the so-called "Baghdad bounce" with an approval rating -- the difference between those who are happy with him and those who are not -- of plus seven.

The ICM poll also showed the Labour party's lead over the opposition Conservatives has narrowed to just two points, compared with a 12 point advantage in a similar poll two months ago.

Meanwhile a YouGov survey released Monday showed 39 percent feel Blair should resign over the Kelly affair.

Kelly's death last week sent shock waves through political circles in Britain and has prompted the media to ask who was to blame for the way the scientist was "outed" as a suspected mole.

The Financial Times reported Tuesday that Hoon had personally authorised a media strategy that led to Kelly being named as the main source for the BBC's story.

The business newspaper said Hoon's direct involvement in the affair meant he could be forced to resign if an independent inquiry criticised the way the government treated Kelly.

The 59-year-old scientist was said by his family to have been under "intolerable pressure" after being grilled by a parliamentary committee over the affair.

Meanwhile, the Independent newspaper reported that Blair's office had overruled a request by defence chiefs not to reveal the identity of weapons expert Kelly.

Defence ministry sources told the Independent that Downing Street forced the ministry to reveal on July 9 that Kelly was probably the BBC's source.

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