Britain's Prime Minister is facing a critical test today as he takes the stand at an inquiry focusing on the death of a top government scientist. The probe is looking into Dr David Kelly's apparent suicide, soon after he got caught up in a row over the government's reasons for going to war with Iraq. Details of Tony Blair's personal involvement in the affair have been slowly coming to light. He has seen his popularity ratings plummet. The latest survey shows 67 percent of those questioned think the government deceived the public over Dr Kelly's death and Iraq's alleged weapons of mass destruction. Yesterday, defence secretary Geoff Hoon faced a grilling at the probe. He said Blair approved a decision to expose the scientist shortly before he died. He said shielding Dr Kelly ceased to be an option after the weapons expert admitted to briefing BBC reporters on a government dossier that is widely seen as having paved the way for war with Iraq. The row began after a journalist claimed the government had exaggerated Iraq's weapons capability. The inquiry so far has shown a series of Blair aides pushed for the report on Iraq to be hardened shortly before its publication. In particular, it has focussed on allegations that the Prime Minister's communications chief Alastair Campbell inserted a claim that Iraq could launch banned weapons at 45 minutes notice. At the defence secretary's prompting, Dr David Kelly was grilled by a parliamentary committee over his unauthorised meetings with BBC journalists. Days later he was found dead in the woods near his home. **British Soldier Killed in Southern Iraq*** Meanwhile, gunmen opened fire with small arms and rocket-propelled grenades on a British convoy trapped between two angry crowds in southern Iraq, killing one soldier and wounding another, the British military said Thursday. The soldiers were returning from a raid when about 30 people blocked their route in the town of Ali as-Sharqi on Wednesday night, British Lt. Cmdr. Richard Walters said. The soldiers moved around that crowd, only to be stopped by a second group of people blocking the road near Fort Jennings, he said. The soldiers got down from their vehicles and fired two warning shots to disperse the crowds when the Iraqis attacked, killing one soldier and wounding the second in the hand, he said. The British arrested 10 people and withdrew to their base at al-Amarah, 75 miles north of Basra with protection from helicopters and additional rapid reaction troops called to the scene, he said. **PHOTO CAPTION*** Tony Blair arrives at the High court in London to answer questions at the Hutton inquiry into the death of weapons expert David Kelly. (AFP/Odd Andersen)