OTTAWA -- The union representing scientists and other professionals in the federal public service is abandoning its tradition of neutrality in elections to actively campaign against Prime Minister Stephen Harper.

The Professional Institute of the Public Service of Canada (PIPSC) says delegates to its annual general meeting have agreed the union should be more politically active heading into next year's federal election.

In particular, delegates have agreed that the union should energetically expose the damage they believe the Harper government has done to federal public services.

Members of the union have complained bitterly about what they claim is the muzzling of federal scientists and political interference with their work.

The union, which represents some 55,000 professionals in the public service, has traditionally chosen to stay at arm's length from elections.

But union president Debi Daviau says the government's war on labour unions and its cuts to public service jobs have forced a change in strategy.

"Extraordinary times call for extraordinary actions," Daviau said in a written statement Friday.

"This government has forced non-partisan organizations such as ours to make a very difficult choice: to remain silent or to speak out. We have chosen to speak out."

Daviau cited several controversial bills as proof that the government has targeted "the very existence of unions and collective bargaining."

A survey commissioned by the union last year found hundreds of scientists who claimed they had been asked to exclude or alter information in government documents for non-scientific reasons. And thousands more said they'd been prevented from talking freely about their work with the media or the public.

"Canadians deserve to know the damage this government is inflicting --unnecessarily and often underhandedly -- to their services, their programs and even to their democracy," Daviau said.