Police officers shouldn’t engage in political activities, and for good reason. It’s vital to democracy that they remain independent and neutral, like judges and Canada’s military.

Unfortunately, that well-understood principle hasn’t stopped unethical election meddling by the association representing 6,000 uniformed officers and 3,000 civilian staff who work for the Ontario Provincial Police.

This union has launched a high-profile publicity campaign against Progressive Conservative Leader Tim Hudak, including two hard-hitting television attack ads airing across Ontario.

The association says this the first time it has taken such action in its 60-year history and felt compelled to do so because of Hudak’s policies, including a proposed civil service wage freeze and changes to arbitration and public sector pensions. But that’s no excuse. This ad campaign is a serious mistake that erodes public confidence in the impartiality of OPP officers.

The Ontario Provincial Police Association should take a lesson from its municipal counterpart in Canada’s largest city. Although Toronto’s police union did at one time endorse election candidates, it no longer does so nor does it issue attack ads.

“The aggravation and the optics around that weren’t good for our membership,” said Mike McCormack, head of the Toronto Police Association. He described the debate over police endorsements as a “quagmire” that’s best avoided. “We’re here to work with whoever might be in political power, no matter how difficult they may be.”

That’s a sound policy and McCormack deserves credit for bringing it about.

When police union leaders condemn a political party’s platform or endorse certain candidates, people readily assume that the average officer shares in this militant meddling. That’s toxic to public trust.

Consider that OPP officers are currently investigating an alleged deletion of emails in connection to former premier Dalton McGuinty’s politically motivated cancellation of a gas-powered generating plant. If these officers now conclude there was no wrongdoing by the Liberal government, there would be unavoidable suspicion in some quarters — however unfair — that political bias had influenced their decision.

This is what happens when police unions wade into electioneering. The Toronto Police Association has learned its lesson — and the union representing OPP officers should do the same.