Blair was warned of post-war instability in Iraq

British Prime Minister Tony Blair was warned a year before invading Iraq that a stable post-war government would be impossible without keeping large numbers of troops there for "many years", secret government papers reveal.

The documents, seen by The Daily Telegraph, show more clearly than ever the grave reservations expressed by Foreign Secretary Jack Straw over the consequences of a second Gulf war and how prescient his Foreign Office officials were in predicting the ensuing chaos.

They told Blair that there was a risk of the Iraqi system "reverting to type" after a war, with a future government acquiring the very weapons of mass destruction that an attack would be designed to remove.

The documents further show that Blair was advised that he would have to "wrong foot" Saddam Hussain into giving the allies an excuse for war, and that British officials believed that President George W. Bush merely wanted to complete his father's "unfinished business" in a "grudge match" against Saddam.

But it is the warning of the likely aftermath more than a year in advance, as Blair was deciding to commit Britain to joining a US-led invasion that is likely to cause most controversy and embarrassment in both London and Washington.

More than 900 allied troops have been killed in Iraq since the end of the war, 33 of them British. More than 10,000 civilians are believed to have been killed. The Iraqi health ministry said a further 45 civilians had died in US air attacks on Fallujah overnight.

Straw predicted in March 2002 that post-war Iraq would cause major problems, telling Blair in a letter marked "Secret and personal" that no one had a clear idea of what would happen afterwards.

"There seems to be a larger hole in this than anything." Most of the US assessments argued for regime change as a means of eliminating Iraq's weapons of mass destruction, Straw said.

"But no one has satisfactorily answered how there can be any certainty that the replacement regime will be any better. Iraq has no history of democracy so no one has this habit or experience."

Senior ministerial advisers warned bluntly in a "Secret UK Eyes Only" options paper that "the greater investment of Western forces, the greater our control over Iraq's future, but the greater the cost and the longer we would need to stay".