Early Downing Street reports suggested that, unlike the Russian President Boris Yeltsin, Tony Blair was one of the few Western leaders to be informed before the missiles were launched against targets in Sudan and Afghanistan.
However, the United States Defense Secretary, William Cohen, said that none of America's allies had been told in advance of the precise nature of the attacks, a claim repeated by Philip Lader, the US Ambassador to London.
Downing Street said that Mr Blair had been informed of events beforehand, but it now appears that the State Department simply warned the Foreign Office that military action was imminent, without specifying where the strikes would take place.
Labour backbenchers took the ambiguity as evidence of Mr Blair's uncritical support for US foreign policy.
The Labour MPs, Tam Dalyell, Tony Benn and George Galloway said that the action had contravened international law and demanded a recall of Parliament to discuss the issue.
Mr Dalyell pointed out that the Foreign Office minister, Baroness Symons, had told the House of Lords in March that there was no evidence of any chemical weapons sites in Sudan.
However, Mr Blair repeated his support yesterday for the American missile strikes with a pledge to "wage war" against terrorism wherever it was found in the world.
He said that the US had the right to defend itself when it was attacked.