Former MP Myron Thompson has ended his longtime association with the Alberta Progressive Conservatives and switched his support to the Wildrose Alliance. (CBC)

A former Reform Party MP and longtime supporter of Alberta's Progressive Conservative party has switched allegiance and is now working with the Wildrose Alliance to defeat the government of Premier Ed Stelmach.

Myron Thompson says the long-governing Tories have moved away from true conservative values and it's time for them to go.

"I want to see some policy changes in this government, a wake-up call to these Conservatives to start being conservative," said Thompson.

The party should "get back to what conservatism is all about," he said. "We have too much government."

Until he retired in 2008, Thompson, 74, served for 15 years as a Reform and then a Conservative MP in the Alberta riding of Wild Rose, a fact that now takes on a particular irony.

He's now on the board of the Wildrose Alliance in his former riding, currently held provincially by longtime Tory MLA Ty Lund, Thompson said.

He has no interest in running for office again himself, he said.

Often seen wearing a trademark cowboy hat, Thompson was one of the most outspoken and socially conservative members of the federal caucus, campaigning for victims' rights and prison reform and against same-sex marriage rights and increases in government spending.

Two Alberta Progressive Conservative MLAs crossed the floor in January to join the Wildrose Alliance led by Danielle Smith.