British Prime Minister Tony Blair says the authority of the United Nations will be destroyed if it fails to force Iraq to disarm. Mr. Blair spoke at the annual meeting of his ruling Labor Party, where many delegates are wary of his support for President Bush's tough stand on Iraq.

Prime Minister Blair told a skeptical audience from his own party that Britain must be prepared for war in the U.S.-led showdown with Iraqi President Saddam Hussein.

Mr. Blair tried to assure the Labor Party conference that his priority is a peaceful, diplomatic solution through the United Nations to ensure Iraq destroys its weapons of mass destruction.

He said he understands the concerns of Labor Party loyalists, who fear Britain is being dragged into an unnecessary war in Iraq. "I know the worry over Iraq. People accept Saddam is bad, but they fear it is being done for the wrong motives. They fear us acting alone. So, the United Nations route. Let us lay down the ultimatum. Let Saddam comply with the will of the U.N.," Mr. Blair said.

But Mr. Blair also asked the delegates to consider what would happen if Saddam Hussein does not comply with U.N. disarmament resolutions. "If at this moment, having found the collective will to recognize the danger, we lose our collective will to deal with it, then we will destroy not the authority of America, or of Britain, but of the United Nations itself. Sometimes, and in particular when dealing with a dictator, the only chance of peace is a readiness for war," he said.

Mr. Blair also discussed the Middle East conflict between the Palestinians and Israel. He called it ugly and wrong. And, to thunderous applause, he said U.N. resolutions should apply in that conflict, as much as they should to Iraq.

The prime minister said final status negotiations between Israel and the Palestinians should be revived by the end of this year. He said the goal should be Arab recognition of Israel, and a Palestinian state based on 1967 borders.