The British Prime Minister, Mr Tony Blair has called for a shake-up of the United Nations and suggested international law may needed changing to allow pre-emptive military strikes.
Blair said international law should allow military action against brutal regimes.
"It may well be that under international law as presently constituted, a regime can systematically brutalise and oppress its people and there is nothing anyone can do," Blair told an audience in his northeastern constituency of Sedgefield.
"This may be the law, but should it be?"
That remark led Blair 's critics to claim he was turning his back on the United Nations - which failed to sanction the Iraq war - and supporting U.S. President George W. 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 UN," said Charles Kennedy, leader of the opposition Liberal Democrats.
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 UN the capability to act effectively as well as debate," he said.
"It means getting the UN 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."
Blair 's decision to back the US-led war on Iraq has been savaged by former government ministers, political opponents and former chief UN arms inspector Hans Blix following the failure to find any weapons of mass destruction (WMD) in Iraq.
Blix added his voice to the latest controversy today, arguing in Britain's Independent newspaper that previous UN resolutions did not provide the legal basis for war.