And then there were three.
Stephen Khan announced late Thursday he is stepping out of the race to become the Alberta Progressive Conservative party's next leader.
Khan made his announcement on Twitter and posted a statement on his website.
"I entered this leadership race because … I believed that we could do politics better than we have in the past," Khan said in his statement. "I was confident that this race would be one of ideas and hope for Alberta's future, and I expected it to be a well-run and principled campaign.
"Instead, it has devolved into vitriol, anger and division. As such, I can no longer participate in this race in good conscience, nor ask my family, volunteers and supporters to do the same on my behalf."
He said the reputation of the PC party has been damaged over the course of this campaign, and he is not sure whether it can be repaired.
PC party executive director Troy Wason said Khan's departure will make things difficult for the party. But Wason said he disagrees with Khan about the reputation of the party.
"He has his reasons, and I respect those," Wason said. "On the other hand, I get emails and phone calls every day saying, 'Hang in there and keep fighting, because Alberta needs a PC party.' "
Wason said he think the three remaining candidates in the leadership race represent a range of views.
Khan's announcement came hours after Wildrose leader Brian Jean announced he is willing to step down from leading his party to run for the leadership of a new, unified conservative party.
PC leadership candidate Jason Kenney was pleased with Jean's announcement.
Fellow PC leadership candidate Richard Starke also announced Thursday he would look forward to working with the Wildrose if he is elected PC leader — but with the parties remaining separate.
In his statement, Khan endorsed Starke as PC leader.
Kenney, Starke and Calgary lawyer Byron Nelson are the three candidates left in the leadership race. The winner will be decided on March 18.