After finding out Ensemble Montréal leader Lionel Perez's son has COVID-19, Montreal Mayor Valérie Plante said Perez should not have been showing up for work at city hall or attending a council meeting while his son was showing coronavirus symptoms.

And Perez should certainly not have been hosting a gathering at his house, Plante said — not just because of his son's condition, but because there is a nationwide call for Canadians to maintain physical distancing to prevent the spread of the virus.

Montreal police were called to the opposition leader's home Wednesday to break up a small outdoor gathering he was hosting to celebrate his daughter's engagement.

In Quebec, police have the authority to issue fines of $1,000 to $6,000 to anyone who does not follow public health guidelines.

"No one is above the law," Plante said, insisting Perez issue an apology and calling on his party to take action to regain public confidence.

Montrealers are cancelling weddings and birthday parties, even funeral gatherings, Plante said.

"If it is not acceptable for the whole of the population, it is also not for the elected officials," she said.

Plante said furthermore, the fact that Perez attended a March 23 council meeting when his son was at home sick "raises questions about his ethics and judgment."

Son tested as soon as he showed symptoms: Perez

Montreal Opposition Leader Lionel Perez says he wanted to bring a bit of hope during what has been a difficult time, by holding a celebration for his daughter and her fiancé, who are in New York. He says everyone respected physical distancing. (CBC)

Perez firmly denies the accusation that his son was ill when he attended that meeting. He said in a statement late Thursday that his son was not showing any COVID-19 symptoms at that time.

The symptoms came only later, Perez said, and the moment his son, who had returned from school in Toronto, tested positive, Perez isolated the family.

"Once I was informed, the whole family was in containment," he said. Perez said he informed the city immediately, on March 29.

Perez said he would have willingly been tested himself, however, because he is asymptomatic, his request for a test was declined. Montreal public health says tests are unreliable when a person shows no symptoms.

Respecting physical distancing

Regarding Wednesday's gathering, Perez said he and his wife and other children were the only ones inside his home.

He had asked a friend to play music from the driveway to help celebrate the engagement of his daughter and her fiancé, who were present by video conference from New York.

Perez said he was respecting physical-distancing measures. Neighbours joined from their balconies, and some passersby stopped to congratulate the couple but stayed outside, Perez said.

"It all lasted about 30 minutes — a short break where my daughter and her fiancé were able to live a moment of hope despite the current crisis," said Perez, who is the city councillor for Darlington in the Côte-des-Neiges–Notre-Dame-de-Grâce borough.

During the gathering, he said his son did go outside briefly, but he called him back in immediately.

When officers arrived, Perez said he co-operated right away, people left the gathering.

Thursday, speaking on Radio-Canada's morning radio program Tout un matin, Perez said he "failed in my role as a leader, to lead by example."

He said he hadn't anticipated the enthusiasm of his neighbours.

"If it were to be redone, I would do things differently, that's for sure," Perez said.

"I have been in politics for 10 years. My trademark is rigour, being meticulous, doing calculated things. It violates my way of doing things, my reputation."

He said it is the first time in his professional life that something like this has happened, and "it will be the last time that I will be responsible for such a situation."