EDMONTON - The gloves came off at Alberta's Progressive Conservative leadership debate Sunday, with three candidates telling former Conservative MP Jason Kenney his plan to unite with the right-leaning Wildrose is cynical and shortsighted folly.

"Folks, this is a hostile takeover of our Progressive Conservative party," candidate Stephen Khan told the 650 people who came to the debate at a southside Edmonton hall, to a smattering of cheers and boos.

PC legislature member Richard Starke referred to Kenney as "the career politician" and said political parties have to be about principles and not simply "a quest for power."

"The career politician is focused on the next election, but I am focused on what happens after that," said Starke, the MLA for Vermilion-Lloydminster.

Kenney is the only one of the four candidates running on a platform to dissolve the party and seek a merger with the fellow right-centre Wildrose party.

Kenney said vote splitting is harming the conservative movement and allowing Premier Rachel Notley's NDP to come up the middle to victory to implement policies that are hurting families, killing jobs and stifling initiative.

Kenney told the crowd Alberta "is the beating heart of free enterprise in Canada and we cannot afford to have that beating heart stilled by an ideological socialist government."

The Wildrose party began more than a decade ago as a splinter group of provincial Tories disaffected with a party they believed had become fiscally wasteful, was governed from the top down and didn't respect private land rights.

While Kenney said he believes all conservatives share core values of limited government and free enterprise, the other candidates say the social conservatism of the Wildrose makes it a poor fit for their big-tent party.

"I can't stand by and allow our conservative family to be torn apart by the contrived and hollow promise of unity," said Khan.

"(It's) an undertaking that will not only result in four more years of NDP rule but will surely be the end of the party that (former PC premier) Peter Lougheed built."

Candidate Byron Nelson, a Calgary lawyer, agreed, saying a merger is "an unrealistic, unworkable plan that will only lead to the destruction of the party and the re-election of the NDP."

Party members will convene March 18 in Calgary to select a new leader in a delegated convention.

The idea has exposed divisions in the Wildrose. Leader Brian Jean is taking a wait-and-see approach, while finance critic Derek Fildebrandt is openly pushing for merger.

PC Party president Katherine O'Neill confirmed Sunday that the party has pulled the party membership of Kenney organizer Alan Hallman for a year and banned him from events during that time.

O'Neill wouldn't say why, but Hallman said it was over two tweets he made where he used coarse language in reference to political foes.

"It's abolutely asinine that they would go ahead and suspend me for something as trivial as a couple of tweets from my private Twitter account," Hallman said Sunday evening.

Kenney said Hallman will no longer be working on his campaign but said a double standard was at work.

"If every member of the party who has said far more vicious things about me were held to the same standard there would be a lot of people losing their memberships," said Kenney.