Montreal's 375th birthday party was fun for tourists, celebrities, and politicians, but municipal workers and activists used it as a chance to air their grievances.

The day began with the installation of four billboards around the city criticizing Mayor Denis Coderre, paid for by Montreal police officers.

Throughout the day protesters held demonstrations in multiple locations, including at City Hall.

Late in the afternoon several hundred white collar workers saying the city is not respecting their current contract.

They were joined by animal rights activists who had a multitude of complaints, including the city's bylaw banning pit bulls, a rodeo taking place in the city later this summer, and the ongoing use of caleches in Old Montreal.

The target of their anger was Coderre himself

"He's launching the 375 festivities today so we decided to present ourselves and make our case," said one protester.

About 500 Montreal police officers gathered during the dinner hour outside their union headquarters on St. Denis St. near Gilford St. The union later said that 3,000 people joined the protest.

Around 7:15 p.m. protesting officers, wearing yellow or red pinneys and baseball caps, marched south on St. Denis toward City Hall.

The protesting police officers did not get much sympathy from onlookers.

Many people who watched part of the march raised their middle fingers to the crowd, while some counter-protesters had signs telling police to quit and get another job if they weren't happy.

Others booed and heckled police, especially those enjoying the warm evening on terrasses.

When the protest arrived at City Hall, union leader Yves Francoeur criticized not just the city of Montreal, but the provincial government of Quebec.

Referring to the years-long refusal of police to wear their uniforms as a protest against their pension plans, Francoeur said "we are about to celebrate with an unconstitutional law regarding uniforms."

There are no indications the provincial law mandating officers wear their proper uniforms is unconstitutional.