LONDON, March 5: British Prime Minister Tony Blair, battling to shake off the damaging controversy of the Iraq invasion, called on Friday for a shake-up of the United Nations and suggested international law may need changing to allow pre-emptive military strikes.

Mr Blair said the row over Iraq - which has sent his public trust ratings plummeting - would never go away, but he stirred up fresh debate with a suggestion that international law should allow military action against brutal regimes.

"It may well be that under international law as presently constituted, a regime can systematically brutalize and oppress its people and there is nothing anyone can do," Mr Blair said in an address to an audience in his northeastern constituency of Sedgefield.

"This may be the law, but should it be?" That remark led Mr Blair's critics to claim he was turning his back on the United Nations and supporting US President George Bush on a doctrine of pre-emptive military strikes.

"I believe many people in this country would be very concerned if Tony Blair thinks he can turn his back on the U.N.," said Charles Kennedy, leader of the opposition Liberal Democrats.

Mr Blair also called for reform of the United Nations and challenged the body, which was divided over Iraq, to stand up to the "terror threat". "It means reforming the United Nations so its Security Council represents 21st century reality and giving the U.N. the capability to act effectively as well as debate," he said.

"It means getting the U.N. to understand that faced with the threats we have, we should do all we can to spread the values of freedom, democracy, the rule of law, religious tolerance and justice for the oppressed."

Mr Blair's decision to back the invasion of Iraq has been savaged by former ministers, political opponents and former chief UN arms inspector Hans Blix following the failure to find any weapons of mass destruction (WMD).

The premier called the row over Iraq "an elaborate smokescreen", saying the real issue was trust, not judgement. The prime minister said his judgement - before the invasion and now - was that the risk of illegal weapons falling into the hands of rogue states could not be ignored, and he signalled he would take pre-emptive action again in the future, if necessary.

"We are in mortal danger of mistaking the nature of the new world in which we live," he said. "This is not a time to err on the side of caution. "Containment will not work in the face of the global threat that confronts us. Emphatically I am not saying that every situation leads to military action. But we surely have a duty and a right to prevent the threat materializing."

"This war is not ended. It may only be at the end of its first phase," he added. Mr Blair has failed to draw a line under the Iraq controversy, despite being cleared of exaggerating the intelligence on Iraq's weapons by an independent inquiry in January.

Mr Blix on Friday added his voice to the latest controversy on Iraq, arguing in Britain's Independent newspaper that previous UN resolutions did not provide the legal basis for invasion.

Mr Blair, under pressure to disclose the legal advice on the issue given by the government's top lawyer, rebutted his critics, saying the advice had been clear. Lawyers would always dispute the legal justification, he added. -Reuters