CALGARY — Tory frontrunner Peter MacKay, not the governing Liberals, was the prime target Sunday during a debate of hopefuls looking to lead the federal Conservative party.

MacKay was attacked as inconsistent for his stand on Iraq and the gun registry, and was depicted as being unable to build bridges with the Canadian Alliance and unite conservatives across the country.

"Peter, during a leadership campaign it's embarrassing when you couldn't decide whether or not to register your gun, but during a national campaign it would be devastating," Nova Scotia MP Scott Brison said during a two-hour debate at the University of Calgary.

"The last leader who made those kinds of flipflops was wearing a wetsuit," said Brison, referring to Stockwell Day's first news conference after taking over the helm of the Canadian Alliance in 2001.

About 200 Tory supporters who showed up to listen to the six candidates got a sharp contrast to Saturday's lackluster Liberal love-fest in Edmonton, where Paul Martin, John Manley and Sheila Copps all agreed to agree on issues of substance.

Calgary lawyer Jim Prentice said MacKay suggested running joint Tory-Alliance candidates in Ontario a day after calling the party "radio-active" in Alberta.

"In parts of the country there is the perception that the policies of the Canadian Alliance are radio-active," retorted MacKay, the son of a Mulroney-era cabinet minister, who at times seemed unprepared for the barbs.

Federal Tories will select a new leader to replace Joe Clark on May 31 in Toronto.

Christian lobbyist Craig Chandler of Calgary stressed the need to work with the Alliance to defeat the Liberals and dismissed MacKay's chances.

"Now Peter, you have done nothing but bring out the rusty artillery of abuse against Canadian Alliance members for an eternity," said Chandler, a small businessman. "You're not going to be able to unite the party and that's facts."

Following the debate, MacKay said he couldn't respond to unfounded allegations.

"If individuals in this race choose to go down a road of negativity, I think that's unfortunate," said the 36 year-old Nova Scotia MP. "This idea that somehow I've been inconsistent or I haven't put forward ideas is completely false."

David Orchard, who is running second among committed delegates, did not attack MacKay.

Orchard said the Tories must stake out "the broad centre ground" if they have any hope of regaining government. He advocated a system of proportional representation to deal with feelings of alienation which are felt in the West and in Quebec.

"That would go a long way toward making people feel their votes count," said Orchard, a Saskatchewan farmer who ran second to Joe Clark in the party's 1998 one-member, one-vote leadership race.

Quebec MP Andre Bachand disagreed with the personal tone of the debate.

"Infighting is not good for any political party that wants to replace the Liberals," said Bachand, noting the Tories have a long road ahead to regain power in Ottawa.

"We need to build bridges inside the party first. Hopefully in the next couple of weeks people will calm down and see what kind of leader we could like who can attract people and not burn bridges."

An earlier Tory debate in Ottawa was described as raucous, stopping just short of hostility among the contenders. But the race to succeed Clark has failed to ignite much interest among the Canadian public.

"Most people aren't paying attention," said political analyst David Taras. "I think the attitude is `wake me up when it's over, I'll take a look at who the leader is and make some judgments then, but don't bother me with it right now.'"

Each of the 310 federal ridings can send 10 delegates to the convention -- many of those selection meetings are already complete.

MacKay leads with the support of 1,166 delegates, while Orchard is second with 709. The other candidates are Prentice, Brison, Bachand, Chandler and Heward Grafftey, a junior cabinet minister in the Clark government who did not take part in Sunday's debate.

There are also about 1,100 automatic delegates such as members of Parliament, legislature members, senators, constituency presidents, former candidates and retired politicians.