Updated

Naysayers to President Bush's talk of war with Iraq would change their tune if they knew how dire the threat is, British Prime Minister Tony Blair said Sunday.

Blair returned to Britain from a hastily-prepared meeting Saturday with Bush at Camp David to discuss Iraq policy to growing criticism of a potential strike against Saddam Hussein.

Blair has been Bush's strongest supporter for an attack on Iraq.

Blair said he understood the critics, saying they "are asking what I call sensible questions" about the international impact of military action, but said he was sure they would be convinced.

"I think people in that second camp can be convinced if they see the evidence, hear the arguments and realize that we're not simply ... striding out on our own, not bothering about other people, but realize that we're going out and trying to win as much support internationally as possible," Blair told Sky news television.

Blair said last week his government hoped to soon publish a dossier of evidence on the Iraqi president's efforts to develop weapons of mass destruction. Washington said it wants to topple Saddam because of his alleged weapons programs. Bush has said his mind is not yet made up about a preemptive strike.

At Camp David, Blair said the United States and Britain would rally "the broadest possible international support" for action to stop Saddam from maintaining biological and chemical weapons or acquiring nuclear arms.

"This is a challenge not simply for America or for Britain but for the whole of the international community," Blair told reporters Saturday.

Other European nations have expressed strong opposition to unilateral U.S. action against Iraq, and some voices in Britain have joined the criticism.

Britain's main union federation, the Trades Union Congress, holds its annual conference beginning Monday and will consider a motion expressing "unequivocal opposition" to military action.

John Edmonds, leader of the GMB general workers' union, said many union members were growing increasingly worried about the threat of war.

"There is an unmistakable feel that the U.S. and U.K. governments are moving toward war," he told Sky News television. "And the overwhelming feeling of the delegates here is that this is not something we should contemplate without total U.N. support.

Rod Eddington, chief executive of British Airways, said Sunday that a war in Iraq could hurt airlines already struggling in the wake of the Sept. 11 terrorist attacks.

The Associated Press contributed to this report.