Montreal police have opened an investigation after demonstrators staged a mock beheading of an effigy of Quebec’s labour minister during a May Day rally, drawing widespread condemnation from political leaders.

Video from the event shows protesters using a guillotine to cut the head off a papier-mâché figure of Jean Boulet before cheering and kicking it.

The Montreal Police Service confirmed an investigation is underway, adding a “deep analysis” of the incident is being conducted.

Chantal Rouleau, Minister Responsible for Montreal, called the act unacceptable.

“It’s terrible that people can do that,” she said, adding “those people must excuse themselves. We are not like that in Quebec,” Rouleau said.

Legal experts say the act could carry potential criminal consequences.

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“I think there could be a potential charge for a death threat. I mean, a guillotine is associated with an execution,” said lawyer Eric Sutton.

He added it remains unclear whether prosecutors would pursue charges, but “the potential is certainly there.”

In a joint statement, major unions including the Confédération des syndicats démocratiques, Confédération des syndicats nationaux, Centrale des syndicats du Québec and Fédération des travailleurs et travailleuses du Québec distanced themselves from the act, calling it an isolated incident.

They said thousands of people took part in the International Workers’ Day demonstration, which they described as peaceful from start to finish.

Premier François Legault said on social media that unions had a responsibility to denounce what happened and noted they did so quickly.

“I am convinced that we will demonstrate that it is possible to move forward constructively without violence or threats,” he wrote.

The group behind the performance, known as the Workers Alliance, defended its actions in a statement, calling it a “carnival-style performance” meant to evoke “a historic symbol of popular anger against out-of-touch elites.”

The group said it believes most people present understood and supported its message, adding “the real threat to democracy isn’t paper-mâché puppets, but policies that primarily serve the interests of the elites.”

The demonstration comes amid tensions following job losses after Amazon’s departure from Quebec, leading to the loss of over 4000 jobs, which the group blamed on Boulet and the CAQ government.

Some Montrealers said the protest crossed a line. “You could agree or disagree with their politics, but it doesn’t have to turn into dragging their heads through the streets. That’s unbecoming of our democracy,” one person told Global News.

Workers Alliance said it will continue to encourage workers to pressure those in power, saying the working class is “done apologizing.”