TOMORROW Tony Blair has the opportunity to demonstrate that Britain is a true friend of the United States.

A true friend does not simply say what the other wants to hear, but offers honest and constructive advice.

When he meets President Bush, Mr Blair needs to warn of the dangers of unilateral action against Iraq.

It is imperative that military intervention against Saddam Hussein attracts the broadest possible international coalition of support.

It is vital that world opinion is lined up against Saddam, and is not in sympathy with him. He must be kept isolated at all costs.

The onus on Mr Blair this weekend will be to convince the President of the need to justify a hard-line stance against Iraq by convincing world opinion beyond any shadow of doubt that Saddam is developing weapons of mass destruction which are a threat to other nations.

The dossier of evidence, proving Saddam is flouting United Nations resolutions, must be presented to the UN. It should be for the UN to sanction any action that needs to be taken.

For the US and Britain to by-pass the UN will destroy the notion of the global unity of purpose to outlaw terror constructed in the wake of September 11.

But as well as a world audience, Mr Blair needs also to address his audience at home.

Within this country public opinion remains unconvinced of the justification to commit our armed forces to a conflict in a far-off land.

The sooner Mr Blair publishes the dossier, the sooner he can begin the task of gathering support for action.

He can no longer ignore the growing and legitimate demands for Parliament to be called to debate the Iraqi crisis.

It is a strange liberal democracy that allows the Prime Minister to be interrogated in his constituency by journalists about the prospect of Britain going to war and allows him to talk freely with leaders of foreign powers, yet denies elected representatives of the British public the opportunity to debate with him.