Thousands of people demonstrate against Quebec Liberal government policies, including university fee hikes and Bill 78 in Montreal on July 22, 2012. (THE CANADIAN PRESS/Peter McCabe)

Quebec's top court denied an appeal of a judge's refusal to block sections of Bill 78.

A coalition including the province's major student organizations and labour unions is challenging the constitutionality of Bill 78, which the government introduced on May 18 in response to the province's escalating tensions over student strikes. The Bill limits the right to demonstrate and imposes stiff fines on organizers who break the law.

A court challenge is expected to be heard later this summer.

In late June, the Quebec Superior Court rejected a request for an emergency injunction against the bill.

It said six sections of Bill 78 do limit freedom of expression but held that an injunction is not warranted because laws are presumed valid, public safety is at risk and the sections don't prohibit protests.

After its defeat, the coalition turned to the Quebec Court of Appeal. On Monday, appeal court judge François Doyon said the lower court did not make any serious mistakes in applying the law and has refused the appeal. Doyon said what's most important is that the trial on the constitutional challenge take place as soon as possible.

No date has been set for the trial and until then the coalition wanted six sections of the law put on hold. Among them, a provision forcing organizers of protests of more than 50 people to give police eight hours notice of the event.