Opposition MPs attacked the Liberals Monday over allegedly misleading the U.S. on ballistic missile defence.

Conservative Leader Stephen Harper told Parliament during question period that Prime Minister Martin "led both our ambassador and the American ambassador to believe the government was signing on, when it wasn't.

"And then he says he rejected the American proposal, yet claims he never actually received one. Mr. Speaker, given all of these stories, how can anyone on either side of the border believe anything this prime minister says?"

Martin was not in the Commons to respond to the questions, but Foreign Minister Pierre Pettigrew said he had informed U.S. Secretary of State Condoleezza Rice of Canada's intentions to not sign on to the ballistic missile defence (BMD) program.

Conservative Deputy Leader Peter MacKay then accused Defence Minister Bill Graham of promising a debate and a vote in the Commons on the issue, and then reneging on that promise.

"Democracy denied, promise not kept," said MacKay -- putting a spin on the "Promise made, promise kept" mantra that Martin repeated often during his Liberal convention speech on Friday.

Graham replied that there was to be a debate in Commons if an agreement was reached with the U.S., but added there was none, so therefore, "There is nothing to debate in the House."

"Our government received cabinet information, we received advice from our officials on both sides of the issue," said Graham.

"In the end, we make a sensible decision in the best interests of Canadians. That's what was done in this case ..."

Martin's position

Denying allegations he flip-flopped on Canada's participation in the U.S. missile defence program, Prime Minister Paul Martin said he never committed because there's never been anything substantial to commit to.

Talking to reporters at a news conference following his party's policy convention in Ottawa Sunday, Martin said that neither he, nor anyone in his government, ever signed on to the American work-in-progress.

On Sunday, Martin referred to the BMD program as an "evolving project . . . good for those who control it," but added: "It's not Canada that will control it."

"And we know well that when you participate in something, the demands can come. There's no one who can explain or quantify them today...

"We didn't want to get involved in something today only to find the situation would be different in two or three years."

Martin's comments came in response to a charge by outgoing U.S. Ambassador to Canada Paul Cellucci -- that Martin had, for some time, sent clear signals he would take part in the missile defence plan.

"We were given that impression in a very direct way for a long time," Cellucci told CTV's Question Period, describing Americans as "perplexed" by Martin's announcement last week that Canada would not take part.

Mixed signals

Watching the prime minister in Ottawa, CTV's Mike Duffy said the confusion may have stemmed from the type of mixed signals one might expect, considering the issue.

"It's all your friends saying 'yeah, yeah, trust us, don't worry about it,'" Duffy said, referring to the diplomatic dance. "But at the end of the day, the decision isn't made until the decision's made."

Nevertheless, in his comments Cellucci said the decision was still Canada's loss, "because they will not have a seat at the table."

"We have this odd situation where the Canadians will participate at NORAD, detecting when the missile is launched, determining where it's heading, and even if they determine it's heading towards Canada, it's at that point they will have to leave the room, because they're not participating.

"In the United States we'll decide what to do about the missile."

Cellucci's interview was recorded last week, before Martin and U.S. President George Bush quieted speculation of strained relations with a phone call Saturday.

More than a week after Martin's phone call to the White House ad first gone unanswered, the two chatted for 15 minutes about defence issues as well as the delay reopening the U.S. border to Canadian cattle.

And when it was over, both sides said they still saw eye-to-eye on cooperation in Norad, the almost-50-year-old air warning command system now set for expansion into maritime and land security.

The pair will get their next chance to hold face-to-face talks on March 23, when they and Mexican President Vicente Fox meet in Texas.