The prime minister has launched a fresh bid to win public support for his stance on Iraq.

Tony Blair admitted he is facing a "difficult situation" but vowed to stand firm against Saddam Hussein.

Warning that the world risks being "plunged into a living nightmare" he said Iraq must now be disarmed.

Blair returned from an Anglo-Spanish summit to tell an audience in Wales that he had real "anxiety" about Saddam Hussein's weapons of mass destruction.

"If we fail this first test.it will not be the end it will only be the beginning," he told delegates. "The humanitarian crisis is not something that we would create; it's already there."

But his speech was met with protests from Welsh Labour members. One delegate said the prime minister should be charged with war crimes if he attacks Iraq without a second United Nations resolution.

Welsh Assembly member Richard Edwards said the prime minister should face the wrath of international law if he launched war without a second resolution

"If they go in without a second resolution, and it looks as if they will, they should be charged with war crimes," he said.

"The war would result in the killing of possibly hundreds of thousands of innocent Iraqi people. If that is not war crimes then what the hell is?"

Speaking earlier in the day during, the prime minister said the result of inaction "would not be peace, it would simply be conflict postponed".

Following this week's rebellion by over 120 Labour MPs, Blair said he could not yield to the demands of domestic and international critics.

Despite the revolt, the Labour leader insisted he still had a strong mandate to act against Baghdad.

"It would be odd if we didn't take into account the fact that we won the vote - and in fact a majority of Labour members of parliament supported the government," he said during a news conference in Madrid.

"I believe genuinely, passionately that international terrorism and unstable repressive states developing chemical, biological weapons are real threats to our security."

He also warned that a failure to enforce the will of the UN would see increased risks from "terrorist groups that will stop at nothing to cause damage and destruction".

The UK prime minister was backed by his Spanish ally, Jose Maria Aznar, who repeated his desire to find a UN solution to the crisis.

"We want a new resolution. We want to find the widest agreement within the security council."

Aznar added that maintaining pressure on Iraq was the "best way to serve peace" and end the "cruel game" played by Saddam Hussein.

Speaking after it was announced that Iraq would begin destroying his arsenal of al-Samoud II missiles, Blair said Saddam was still playing games with the United Nations.

"The moment I heard earlier in the week that Saddam Hussein was saying he would not destroy the missiles was the moment that I knew later in the week that he would announce, just before Dr Blix reported, that he would indeed destroy those missiles," said Blair.

"This is not a time for games... he knows perfectly well what he has to do. He could start by telling us what has happened to the unaccounted for material that everyone knows was there when the inspectors left.

"The question is does he have the will to do it?"

The prime minister said that the Iraqi president never makes any concession without the "threat of force hanging over him".

Blair also insisted that Iraq had chemical and biological weaponry which could fall into the hands of terror groups.

"Sometimes that threat is difficult to discern in an immediate sense - but it is real," he said.

Failing to act "would put at risk not just our security but our prosperity for the future".

The comments came after two-days of talks between Blair and his Spanish counterpart.

Spain has been one of the key European supporters of the stance on Iraq adopted by American and Britain.

The centre-right Spanish government is one of the co-signatories of the latest resolution drawn up by the US and Britain in a bid to bring the current crisis into its final phase.

Other issues included in the discussions were plans for greater liberalisation of European economies and prospects for reforming the workings of the EU.

The two leaders also issues a joint paper on the need to step up cooperation to deal with the problem of illegal asylum seekers.