"I have received several disturbing emails and phone calls over the last couple of weeks, including a death threat left on my personal voice mail," Rob Anderson posted to his Facebook page Thursday.
"I have provided the recording and details to local law enforcement and they are currently investigating.
"The RCMP has been very thorough throughout this process and has provided increased security and monitoring of my office and personal residence."
Anderson, who now sits as a backbencher, could not be reached and a spokesperson for Premier Jim Prentice declined comment.
Alberta RCMP spokeswoman Sgt. Josee Valiquette wouldn't say if an investigation is underway.
Earlier this week, Anderson announced he will not seek re-election, in part because of the angry reaction that followed his decision last month, along with eight other Wildrose party members, to join Prentice's Progressive Conservatives.
The move left the official Opposition with five legislature members compared with 72 for the Tories.
It also brought a fusillade of public criticism. Some have characterized the former Wildrosers as opportunistic sellouts who abandoned the democratic principle that strong governments involve healthy opposition.
"Although this experience has been very difficult for (my wife) Anita and I, we want you to know that our family is safe," Anderson said on Facebook.
"We also want to thank the many friends and supporters that continue to reach out with such kindness, and acknowledge that the majority of people who have disagreed with my decision to join the government have done so in a respectful manner.
"We will not let a few extremists cloud our view of the people and community we have come to love so dearly."
Anderson, a two-term member of the legislature, said he will focus on helping Prentice craft the next budget and advocate for 24-hour health care in his Airdrie constituency.
Anderson joined the Tories along with Wildrose leader Danielle Smith and seven others on Dec. 17. It was a second crossing for Anderson, who was elected as a PC member in the 2008 campaign, but quit to join the Wildrose two years later.
Anderson and Smith have been singled out for heightened criticism because she was head of the party and he was her house leader.
There have been conflicting reports on whether the nine were promised cabinet posts or guaranteed PC nominations in return for abandoning the Wildrose.
A draft agreement leaked before the floor-crossings promised that Prentice would lend his support to the candidates. The PC president in Smith's Highwood constituency has already said there will be an open nomination.
New Wildrose house leader Shayne Saskiw said Thursday he doesn't know what was promised because he dropped out of the plans to switch midway through.
But he said the mass defection was Smith's idea. She directed Saskiw to initiate a move by meeting with Prentice's chief of staff, he said.
"I had some of the initial conversations, but in the end I can't tell you which individuals were promised what."
Smith could not be reached for comment.
As for Anderson, Saskiw said "any type of threats like that are inappropriate whether it be a politician or a private citizen."
NDP Leader Rachel Notley declined comment, but said "all Albertans are deeply troubled by what happened (with the floor cross).
"And they're not just troubled by the actions of the Wildrose. They're also troubled by the actions of Jim Prentice (in accepting them)," she said.
"It is profoundly disrespectful to the democratic process."
The Wildrose have 19 of 87 candidates in place for the next election.
While the vote is set by legislation for the spring of 2016, Prentice has refused to close the door to holding it as early as this spring.
Saskiw said that would be a mistake, given that Prentice promised during last year's PC leadership campaign to follow the rules.
"People of this province expect all MLAs right now to be focused squarely on dealing with issues at hand, such as the looming financial crisis (of low oil prices)," he said.
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