Alan Simpson: Blair is sailing away from the Labour Party

The Ark Royal wasn't the only ship to sail this week. A flotilla of smaller craft has already begun to set off on a different course. It is made up of Labour's constituency parties and affiliated trade unions, sailing in opposition to a war against Iraq that the Labour leadership seems destined to support if President Bush gives the call.

No one should underestimate the chasm opening up in Labour's ranks. The Iraqi-style democracy of New Labour means that a leadership challenge is not constitutionally possible. Talk of stalking horses is just silly. The simple truth is that the Prime Minister may take Britain into America's war but he will not take the party with him.

The official riposte to such a claim is that it is only "extremists" in the party that oppose the war. In reality, it is only the extremists who would take us into one. Historically, Labour leaders have always counselled against presumptions that war was the answer to an international crisis.

Keir Hardie and Ramsay MacDonald opposed the First World War on political grounds. Attlee warned President Truman against a nuclear attack on Korea. Gaitskell opposed a war over Suez and Harold Wilson, though he would not condemn the US, refused to commit British troops to fight in Vietnam. Today, Britain's troop deployments provide the spurious internationalism that covers for George Bush's intention to bomb.

It isn't simply that the arms inspectors have given the thumbs down to every weapons site named in British and American dossiers on weapons of mass destruction. All the major churches are cautioning that even if you took your own weapons to "find" in Iraq, you would still not have sufficient grounds for assuming that a war would be justifiable, let alone unavoidable.

Press conferences in Downing Street and briefings from the White House are becoming frighteningly Messianic in tone. The case for war becomes a mantra rather than a credible explanation. Iraq apparently has to be crushed to prevent some unspecified future atrocity we have yet to be threatened with. Until Bush's "axis of evil'' speech this would have been regarded as a poor joke. Now it is packaged as the thread upon which civilisation itself hangs.

The problem for Bush and Blair is that they look increasingly like men on a personal mission, no longer dependent on a popular mandate. At some point in this trajectory you have to ask when a person begins to look more Mullah than Messiah.

Al-Qa'ida's appeal was to a similarly "higher cause''. All it asked was a fundamentalist acceptance that an external evil had to be brought to its knees. No provocation was needed beyond the claimed existence of this evil. Evidence was not important, only certainty. In Bush's case it also raises the question of why we should continue to chase al-Qa'ida when it is easier to become them?

The scope for avoiding such a foolish and destructive war lies not with Saddam Hussein but with us. A perverse coalition of the interests of God and Mammon could yet save the day. No one should underestimate the opportunity the Prime Minister has for giving a moral lead in America. Tony Blair may be the one person with a real veto over US war plans.

American public opinion on war is brittle. The substantial majority in favour of a war becomes a similar majority against when the question becomes: "Should the US go it alone?" The American anti-war movement constantly bemoans the fact that it is the Blair endorsement that stands in the way of their ability to make this change.

Mammon, however, may step in where Labour fears to tread. Economists have been warning that a war would simply accelerate the economic crisis that will hit the US sometime this year. US foreign debt currently runs at over $260bn and is scheduled to double (to 50 per cent of America's GDP) over the next five years. Bush's funding for a war would be done by further government borrowing rather than taxations.

During the last year the dollar has fallen by 9 per cent. A war – and the spending gap itself – will just bring forward the date of a second fall in dollar values. Governments, companies, pension and insurance funds are already questioning the wisdom of holding dollar assets (and government "war" bonds) when the the war-bubble bursts.

None of this relies on the boycott of American goods now spreading across the Middle East, with sales of the targeted products down by up to 40 per cent. It recognises the Achilles heel in Bush's dreams for a new American imperium. Like his daddy before him, Bush will be a one-term washout if he fails to sort out the economy.

So go ahead. Whether for God or for Mammon, pull your pension funds and investments out of the dollar. Avoid the rush (and loss) that will come later. Whether out of self-interest or moral principle, hit the President's wallet and you will reach the President's ear. It is the only pre-emptive strike worth making. Not a single life lost. Not a single bomb dropped. Not a single propaganda gift to terrorist movements. Go on, make my day.

The author is the Labour MP for Nottingham South