Opposition MPs hammered the Liberal government on Friday about why Parliament wasn't consulted in the decision to not join the U.S missile defence program.

"The prime minister broke his promise to Parliament when he said there would be a vote," an angry NDP leader Jack Layton told the House of Commons during question period.

"Who's going to resign over this fiasco?"

Conservative Deputy Leader Peter MacKay, echoed frustrations that Paul Martin's government had acted without bringing the issue before Commons.

"The minister of defence, as recently as Tuesday, said any decision about missile defence would be discussed with members of the House," MacKay reminded the Liberals.

"While the marginalized minister of defence was assuring us of this, the foreign affairs minister was telling Condoleezza Rice we wouldn't participate."

MacKay demanded answers why Parliament was "so out of the loop."

Keith Martin, the parliamentary secretary for defence, said the Liberals only promised to bring the matter to Parliament "when there was an agreement to be signed. And there's no agreement."

After Martin announced his decision about the program on Thursday, reaction was stern and swift from Washington.

U.S. ambassador to Canada, Paul Cellucci said that from now on, the U.S. will decide when to fire at incoming missiles over Canadian territory. "We will deploy. We will defend North America," Cellucci said.

"We simply cannot understand why Canada would, in effect, give up its sovereignty -- its seat at the table -- to decide what to do about a missile that might be coming towards Canada."

Shortly before Friday's question period, a defiant Martin said Canada would have to give permission before any missiles are fired over our airspace.

"We would expect to be consulted," Martin told reporters in Ottawa. "This is our air space. We're a sovereign nation and you don't intrude on a sovereign nation's air space without seeking permission."

But his strong words did little to blunt criticism and skepticism in the House.

Conservative MP Gordon MacKay said the prime minister's insistence on being consulted is "delusional."

"How can the prime minister realistically believe the U.S. will consult him?"

Foreign Affairs Minister Pierre Pettigrew also faced questions on Canada AM about shooting down a missile that might be in Canadian air space.

Pettigrew called it a "hypothetical question" and said Canada's defence policy is aimed at making sure that scenario never happens.

"We have identified our priorities in defence and security," Pettigrew said. "We believe that we should not contribute to the proliferation of nuclear weapons."

Also on Canada AM, Wall Street Journal reporter John Harwood said Canada will pay a price for not signing on to missile program, and the most likely area affected could be trade.

"One ramification of this is potentially some added tension on one of the other issues affecting Canada-U.S. relations, especially trade."

Harwood said on the surface, little will change, but Paul Martin's decision could spark a slow burn with the Bush administration.

"What this underscores is that there are limits to the fence mending that the president is trying to do with Canada and with countries in the European Union."