Alberta Premier Rachel Notley says the NDP would welcome anyone who feels like they wouldn't have a political home in the United Conservative Party.
The province's two right-leaning parties recently signed a deal to merge, but the union needs approval from both Progressive Conservative and Wildrose Party members this summer to go ahead.
If that hurdle is cleared, there is to be a leadership race on Oct. 28.
In a speech at an NDP fundraising cocktail reception in Calgary on Thursday, Notley took numerous digs at PC Leader Jason Kenney and Wildrose Leader Brian Jean, who both want to run the new merged party.
She said both Kenney and Jean are getting more extreme in their views, and some long-time members may be feeling underwhelmed, frustrated and disgusted by their tactics.
Notley's speech made no mention of Calgary lawyer Doug Schweitzer, who announced earlier in the day he plans to seek the UCP leadership if the merger goes ahead.
"I know I'm not alone in believing Albertans deserve better — much better," Notley said.
"And to those Albertans who are feeling like they don't have a political home... I ask you to take another look at our government, our party and our record."
She said the economy is recovering, pipelines have been approved and infrastructure is being built.
"Regular Albertans, for once, have a government that's in their corner, working to make life better. So if you feel without a political home, we would welcome you."