Thousands of protesters on foot, bicycle, skateboard or rollerblades, crossed Montreal late on Saturday to the deafening din of pots, fog horns and whistles in protest at new rules limiting their right to demonstrate.
Some carried Quebec flags, others red flags and placards denouncing the special law, hastily passed a week ago, intended to clamp down on a wave of student protests against rising tuition fees.
The emergency law requires protest organisers to give police at least eight hours advance warning of times and locations of demonstrations, with big fines for failure to do so.
Authorities had used the law to declare protests illegal, clearing the way for police to disperse protesters.
But about 10,000 people joined Saturday's demonstration, including some dressed as clowns, a man dressed in a panda costume and a young naked woman riding a bicycle.
A small police escort followed behind on horseback, by bicycle and by car.
While students formed the bulk of the protest, there were also some senior citizens who found some creative ways to show their discontent.
"I am 71 years old and I went to study at Paris just after May 1968," said Guytay Tremblay, a professor of art who was dressed as the Statue of Liberty.
Many marchers said the special law was just one of several reasons for their presence.
"For months we hear of various scandals, corruption," explained Jocelyn Simard, a retired professor of philosophy.
"People listen to it on television but they feel helpless. I think students have encouraged people to take to the streets to express their rejection of political corruption."
The march was immediately declared illegal by police, who had not been informed of his itinerary.
But the demonstrators were able to proceed without incident and the only arrest made was that of an irate driver annoyed at being blocked by the protesters, police said.
Similar events were held in Quebec City, Trois-Rivieres and in several other cities in the francophone province.