Ministers face the real prospect of waging an illegal war, which could lead to British soldiers being prosecuted by the newly constituted International Criminal Court (ICC).

The shaky legal grounds upon which Britain and America are expected to launch their military offensive have already been exposed by the UN secretary general, Kofi Annan.

But Mr Annan's warning that military action against Iraq without a second UN resolution would be illegal is being supported by a growing number of senior British lawyers.

Stephen Solley QC, an international human rights lawyer, said yesterday: "I feel this is a defining moment in our history which our children will want to ask us about. No one has made a legal case for war."

But he said it was also clear British troops could be the first to face war crimes charges at the ICC. The court, which was formally opened in the Hague yesterday, has the power to bring to trial individual soldiers, commanders and politicians charged with war crimes.

International lawyers argue that any military attack that killed Iraqi civilians could lead to British soldiers being prosecuted at the new court.

But because America and Iraq are not signatories to the Rome treaty, which created the ICC, their soldiers are immune from prosecution.

The Attorney General, Lord Goldsmith, is known to have advised the Prime Minister on the legal issues surrounding the prospect of war, but it is understood that the risk of soldiers being prosecuted by the ICC is of most concern.

Military action in breach of UN resolutions would mean little if the sanction constituted no more than a finding that the UK was in violation of international law.

But potential sentences of life imprisonment for soldiers acting on the orders of the Prime Minister will have concentrated the minds of the Government's law officers. Peter Carter QC, chairman of the Bar's human rights committee, said British commanders would have to "adapt a very different attitude to their American colleagues so they can justify every military act of attrition against every target." He said it could cause real difficulties in joint actions between the forces.

Mr Solley says British troops will feel "vulnerable" to war crimes charges. "No one thought when they were planning the ICC it would have to consider the consequences of a unilateral invasion by America and Britain of another country."

James Crawford, a professor at Cambridge University and a member of Cherie Booth's chambers Matrix, said it was important to realize no "criminal charges" could be brought against Britain or America for a use of force that breached UN or international law. But he added that, under the terms of the ICC, British soldiers and commanders could be prosecuted for war crimes.

In the past few weeks, legal opinion has become increasingly unified in the belief that the US and its allies cannot rely on the principle of anticipatory self-defense to justify action against Iraq in the absence of a fresh UN resolution.

Article 51 of the UN charter allows self-defense only if an armed attack occurs against a member state and, even then, only until the Security Council has taken action.

War within the law?

Suez

Illegal invasion planned in secret by UK and France with Israel after Egypt nationalized Suez canal. France/UK persuaded the UN to order ceasefire plan but the invasion was scrapped amid domestic and US opposition.

Falkland Islands

Acting in self-defense under UN charter, Britain sent a task force to recover the Falklands, violently occupied by Argentina in April 1982.

Kuwait

UN Security Council adopted resolution 678 in November 1990 providing for "all necessary means" to roll back the Iraqi invasion of Kuwait.

Kosovo

Acting without explicit UN approval, Nato carried out an 11-week bombing campaign against Serbia, citing humanitarian imperatives, to force Slobodan Milosevic to end persecution of the ethnic Albanian majority in Kosovo.

Afghanistan

Acting in self-defense under UN charter, the US and Britain launched action against the Taliban after Afghan rulers refused to hand over Osama bin Laden, blamed for 11 September attacks.

© 2003 Independent Digital (UK) Ltd

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