OTTAWA - While chieftains at the government's largest union celebrated a separatist victory in Quebec on Wednesday, a Conservative MP said he will push for legislation to allow workers to opt out of paying dues.

Ottawa MP Pierre Poilievre says by supporting the Parti Quebecois and Quebec Solidaire and other activities, the NDP-friendly Public Service Alliance of Canada (PSAC) is not acting in the interests of the majority of its 172,000 members.

Poilievre's riding is home to thousands of government workers - some of whom have expressed their disbelief to him over the use of dues to fund political and militant activity, including supporting student protesters in Montreal.

He says he will advocate for passage of a private member's bill in Parliament that would force unions to open their books to learn how dues are spent.

And while he is a parliamentary secretary and can't introduce private bills, he will encourage and help others draft legislation that would allow union members the choice of paying dues.

"It stands to reason that the law should not force workers against their will to pay union dues to radical causes of PSAC union bosses," he said.

"Workers should have the right to know how their union dues are spent and if they don't like what they see, the freedom to opt out of paying them."

PSAC's hostility to Conservative government budget cuts reached new heights last weekend when the union hired a plane to tug a streamer reading, "Harper Hates Us" -- a stunt the union says it plans to repeat when MPs return from summer recess.

PSAC president Robyn Benson said members vote on how their dues are spent every three years, including money for political action, and pointed to a Supreme Court ruling that upheld the right of unions to collect dues, except in the case of religious objection.

"Mr. Poilievre is raising this issue now to distract from the fact that he and his government have been cutting valuable public services and good jobs without being transparent to Canadians," she said.