SADDAM HUSSEIN was warned last night that he faced the moment of truth after it was announced that Britain is to assemble a massive 30,000-strong land force in the Gulf ready to take part in a possible invasion of Iraq.

Defence Secretary Geoff Hoon told MPs yesterday that 26,000 troops, including detachments of Paras and the Desert Rats, were to be deployed to join 4,000 Commandos already sent to the region.

Mr Hoon said they would provide "a high-readiness, balanced and flexible force package, bringing together a wide range of capabilities".

"The Chiefs of Staff and I are confident that this is the right group of forces for the sort of tasks that may be necessary," he told the House of Commons.

Mr Hoon acknowledged that the deployment - the largest since the Kosovo conflict - was "no ordinary measure". But he insisted it did not mean war was inevitable.

"None of the steps we are taking represents a commitment of British forces to military action," he said. "These are measures necessary to provide a range of options.

"A decision to employ force has not been taken, nor is such a decision imminent or inevitable."

The massive land force, which will join more than 100,000 US troops in the Gulf, piles pressure on Iraqi dictator Saddam to comply with UN demands to eliminate any weapons of mass destruction programmes.

Iraqi officials yesterday agreed with the chief UN arms inspectors on practical steps towards fulfilling their obligations to disarm.

The developments, which came after two days of talks in Baghdad, included Iraq encouraging its weapons scientists to submit to private UN interviews - a key American demand.

The British deployment announced yesterday included Headquarters 1 (UK) Armoured Division, with support from 7th Armoured Brigade - the Desert Rats - 16 Air Assault Brigade and 102 Logistics Brigade.

Among the troops are about 6,000 front-line combat troops.

They will be equipped with 120 Challenger 2 battle tanks, 150 Warrior armoured personnel carriers, 32 AS-90 self-propelled guns and 18 light guns and a number of other reconnaissance and other vehicles.

Mr Hoon said that deployment would take place by air and sea "over the days and weeks ahead".

Britain's largest naval task force since the Falklands, led by the aircraft carrier HMS Ark Royal and carrying 3,000 Royal Marines and 5,000 sailors, has already set sail for the Mediterranean.

Foreign Secretary Jack Straw warned yesterday that time was running out for Saddam. He told a counter-terrorism meeting of UN Security Council foreign ministers in New York: "The moment of choice for Saddam is close.

"He must either resolve this crisis peacefully, by the full and active compliance with his Security Council obligations and full co-operation with inspectors, or face the 'serious consequences' - the use of force - which this Council warned would follow when it passed (Resolution) 1441."

Mr Hoon said additional reservists would also be called out to support the land troops.

Shadow Defence Secretary Bernard Jenkin gave the Tories' full support for the deployment.

But he raised concerns over whether the troops involved were "fully trained and fully equipped" for whatever tasks they may be asked to perform.

Mr Jenkin called on the Government to furnish them with "friend or foe" identification systems to prevent a repeat of the "friendly fire" deaths in the 1991 Gulf War.

* Support for war has fallen to its lowest level yet, according to a poll to be published in The Guardian today. Only 30 per cent of those questioned by ICM said they would approve of a war - down six points in four weeks.