Prime Minister Stephen Harper was slammed repeatedly yesterday during the opening ceremonies of AIDS 2006 for his absence at the international forum.

Event co-chairman Dr. Mark Wainberg, an AIDS expert from McGill University in Montreal and actor Richard Gere took shots at the PM for being a no-show.

"I think it's an embarrassment," Wainberg said during his opening address.

"I think he's made a mistake, quite honestly."

Gere said Harper will regret his decision not to attend the event, much as former U.S. president Ronald Reagan regretted his long silence on the issue.

"I think you have a prime minister who's going to be deeply apologetic," he said to enthusiastic applause at the Rogers Centre, where more than 24,000 converged.

"I think the worst thing a leader can do now is send mixed messages to the people. We need unequivocal leaders who tell us the truth, who tell us it boldly, tell us we're all in this together and we can beat this together."

Two Liberal leadership hopefuls stood outside the Rogers Centre and chided Harper for his behaviour.

Scott Brison, a Nova Scotia MP, said Harper's decision not to attend the conference sends a clear message to Canadians about the government's stance on HIV/AIDS.

"Stephen Harper's absence here tonight demonstrates a shocking lack of leadership and an appalling lack of compassion," Brison said.

St. Paul's MP Carolyn Bennett said she believes Harper decided not to attend because of the stigma attached to AIDS, and the connection between it and homosexuality.