General Motors has been locked in a war of words with the Canada’s Unifor union ever since the automaker announced plans to idle the Oshawa assembly plant.

That battle continues, but GM has found itself in the awkward position of amplifying the union’s anti-GM message. The latest issue involved a Super Bowl commercial that Unifor planned to air in Canada during last night’s Super Bowl. As the union explained yesterday, the automaker’s lawyers contacted them and demanded they “cease and desist from any further communication” of the commercial called “GM leaves Canadians out in the cold.”

In the letter (PDF), dated February 1st, lawyers for GM Canada complained the ad “contains several statements that are knowingly false and misleading” and is “clearly intended to promote Unifor’s business interests and calculated to disparage GM’s business interests.”

GM Canada’s main complaint appears to center around the claim the Canadian government gave the automaker $10.8 billion CAD ($8.2 USD). GM points out this wasn’t a gift, but rather an interest bearing loan that was eventually paid back. GM also took issue with the ad for suggesting each Canadian gave the automaker $300 CAD ($228 USD) and for saying the company is greedy.

While ad seems pretty clear to people familiar with the situation, lawyers demanded that Unifor remove all copies of the ad from “publicly accessible media” such as social media and YouTube. The lawyers went on to demand the ad not be shown in the future.

Unifor National President Jerry Dias didn’t back down and the commercial aired during last night’s game. As Dias explained, “We stand by the belief that if GM wants to sell here, then it needs to build here and we will not be intimidated from sharing that message with Canadians in this ad.”

It remains unclear if GM Canada will pursue the issue further, but yesterday the company released a statement saying “While GM respects Unifor’s rights to protest, we cannot condone purposely misleading the Canadian public.” The company went on to call the ad “misleading and inaccurate” and claim GM has contributed over $100 billion CAD ($76.2 billion USD) to the Canadian economy since 2009.

While GM might prevail in an extended legal fight, the company has effectively discovered the Streisand effect. By fighting the ad, which was only slated to be shown to Canadians, they effectively promoted the anti-GM message to an international audience.