The dispute over Quebec's proposed pension reform legislation took a new twist overnight Friday when more than 100 Montreal officers simultaneously called in sick.

The situation sparked a 2 a.m. emergency meeting between Quebec’s labour board and the police union — the Montreal Police Brotherhood — that lasted until 6 a.m Saturday.

The meeting concluded with the labour board ordering all officers back to work.

A police department spokesman said police services were not compromised by the move and those already on duty filled in by working four hours of overtime.

Other officers came in four hours early.

It is not clear how much the overtime will cost the city.

The Police Brotherhood denied encouraging its members to call in sick.

Quebec Municipal Affairs Minister Pierre Moreau suggested the pressure tactic was illegal and said it was not acceptable from authority figures such as police officers.

"It's important, especially when you're a police officer, you're invested with authority according to our society and whenever you act illegally, you jeopardize the confidence of the public in the institution itself," he told CBC News.

Officers and other municipal workers have been using pressure tactics in recent weeks as they protest proposed pension reform legislation.

The Quebec government has introduced legislation known as Bill 3 that would increase the share of pension contributions paid by municipal workers to 50 per cent.

A demonstration outside of Montreal’s city hall on Friday saw police and firefighters throw their service shirts on the building’s steps.

Police officers and other municipal workers have also been wearing casual pants and red baseball hats as a symbol of protest against the pension reforms.