The Government last night urged all remaining Britons to leave Iraq as the leaders of England's two main churches challenged Tony Blair's moral case for war.

The Archbishop of Canterbury, Dr Rowan Williams, and Catholic Archbishop of Westminster Cormac Murphy-O'Connor issued a statement calling for a continuation of weapons inspections.

And they warned of the "unpredictable humanitarian and political consequences" of war.

Their statement came after a week in which the Prime Minister has repeatedly argued "the moral case" for removing Saddam, arguing it would be inhumane to allow Saddam to remain in power, because of the suffering he would cause his people.

But the churchmen's statement expressed "deep disquiet" about the possible consequences of an attack.

It said: "The events of recent days show that doubts still persist about the moral legitimacy, as well as the unpredictable humanitarian and political consequences, of a war with Iraq. We recognise that the moral alternative to military action cannot be inaction, passivity, appeasement or indifference.

"It is vital therefore that all sides in this crisis engage, through the United Nations, in a process, including continued weapons inspections, that could and should render the trauma and tragedy of war unnecessary."

Meanwhile, the Foreign Office - which has long warned against any travel to Iraq - yesterday updated its advice to urge Britons to get out now, citing "increasing regional tension" and the risk of terrorism. It is estimated that there are between 150 and 250 Britons still in the country.

They include journalists and "human shields" - anti-war volunteers hoping their presence will deter an attack.

* About 1,000 paras, infantry and support troops from the 16 Air Assault Brigade left RAF Brize Norton in Oxfordshire for the Gulf.

The latest troop deployment will take the British military presence in the region to about 19,000, comprising 9,000 soldiers, 8,000 sailors and Royal Marines with 2,000 from the RAF.