Nathan Cooper has been chosen by members of the PC and Wildrose caucuses to serve as interim leader of the new United Conservative Party.

The Wildrose MLA from Olds-Didsbury-Three Hills will serve in the post until a permanent leader is elected on Oct. 28.

The two caucuses met at the Federal Building in downtown Edmonton Monday afternoon, with 22 MLAs attending in person and others on the phone.

Cooper described the tone of the meeting as "fantastic."

"We've been working well together over the last number of months, certainly last session," he said. "There are so many great people that are part of both organizations, and so the relationships are strong."

ALTA WILDROSE PC MERGER 20170724

Brian Jean, left, and former house leader of the PC's Ric McIver sit together during the first meeting of the new United Conservative Party caucus in Edmonton on Monday. Jean resigned as Wildrose Party Monday morning and formally announced his leadership bid later that day. (Jason Franson/The Canadian Press )

Brian Jean attended in person for half an hour before leaving for Airdrie, where he formally launched his leadership campaign. 

Jason Kenney did not attend. He is not a member of the PC caucus because he is not an MLA. 

Kenney is expected to announce the start of his leadership campaign on Saturday. 

'Who can beat the NDP?'

Jean told the crowd at his leadership launch that he resigned as Wildrose leader on Monday morning.

If he becomes premier, Jean said his first action would be to end the province's carbon tax. He also vowed to hold a referendum on equalization among provinces within a year of taking office. 

When asked to compare himself to Kenney, Jean said the leadership race will be about winning the hearts and minds of Albertans to lead the UCP to victory in the 2019 provincial election.  

"Really the question is, who can beat the NDP?" he said. "And I believe I am that person."

'Red flags'

On Saturday, members of the Wildrose and Progressive Conservative parties ratified an agreement to merge under the UCP banner by a margin of 95 per cent.

The new party was expected to register with Elections Alberta late Monday afternoon or on Tuesday morning.

Former Progressive Conservative cabinet minister and leadership candidate Richard Starke announced Monday he will not join the UCP, saying he doesn't think moderate views will be welcome. 

Starke, the MLA for Vermilion-Lloydminster, said there were a number of red flags for him since Kenney won the PC leadership March 18. They included ambiguity on gay-straight alliances, PC Leader Jason Kenney's decision not to take part in the Edmonton Pride Parade and statements on social media by PC party president Len Thom likening changes to the social studies program in Alberta schools to the Hitler Youth.

"As a veterinarian, at some point if there are so many clinical signs, you have to make a diagnosis," he said. 

Starke said he volunteered to be on a committee to advise the PC members on the unity working group. He said that committee was never formed. The deal to unite with Wildrose and created the UCP was announced May 18. 

Starke said he notified the Speaker of the legislative assembly of his intentions not to join the new party. He will continue as a PC MLA. That may change if the PC board de-registers the party. 

Starke, who came a distant second to Jason Kenney in the PC party's spring leadership race, has been silent on his views ever since the two parties reached the unity agreement on May 18.

The MLAs at Monday's meeting said they did not talk about removing Starke from the PC caucus. 

Also on Monday, longtime PC strategist Susan Elliott told the Calgary Eyeopener she would be leaving to join the Alberta Party. 

"I feel that my party voted itself out of existence over the weekend and so I'm a free agent and I've chosen to join a new team," said Elliott, who ran the PC's successful 2012 campaign under Alison Redford and was the director of communications during the 2008 election.

"I'm doing that in part because I think that's where Alberta voters are. I've been saying this for a very long time, it won't come as a surprise to anyone, I believe that most Albertans are fiscally conservative but they are socially moderate and modern on issues of conscience as well as issues of giving people a hands up and helping."

With files from the CBC's Kim Trynacity