Quebec's legislature unanimously supported a motion Tuesday condemning the massive disruption of construction work across the province, as a showdown between the government and building unions left work sites idle for a second straight day.

All members of the national assembly voted in favour of Labour Minister Lise Thériault's motion, calling for an end to work site vandalism, worker intimidation, and a return to work.

"It's hard to believe it is not planned — very hard," she said Tuesday.

Dozens of construction sites sat virtually empty for a second day, as unionized construction workers staged more protests against Bill 33, the Liberal government's proposed reform for construction union rules.

Bill 33 would limit union powers over job placement on construction worksites in Quebec, and would force unions to open their books to outside audits and public scrutiny.

The sudden work stoppage by members of two major unions began Monday morning, sparking a war of words between the province, the two unions, and construction workers.

Most of the 500 workers building the McGill University Health Centre's superhospital in Montreal's west end did not show up for work Tuesday, while others were forced out by groups bearing union insignia who refused to comment. Police cruisers monitored the scene.

Similar situations unfolded at the downtown site of the Centre hospitalier de l'Université de Montréal (CHUM) superhospital, and at other construction zones across the province.

Commission hears from unions

Construction worker Sylvie Déraspe spoke at Quebec's national assembly Monday about physical intimidation of a fellow worker. (CBC)The province-wide protest comes as a parliamentary commission holds hearings on Bill 33 in Quebec City this week.

Quebec's most powerful construction union federations – the FTQ-Construction and International (CPQMCI) – have been outspoken about their opposition to Bill 33.

Construction unions are concerned Bill 33 will "be like going back to 1920" and will strip unions of powers that have long served workers well, said Paul Faulkner, a manager with construction union International (CPQMCI).

Allegations of physical intimidation came to light at the commission hearings Monday.

Construction worker Sylvie Déraspe told the commission that female workers are subject to harassment and discrimination, and that union-controlled job placement was to blame in part. Déraspe said her colleague Lucie Hounsell was supposed to testify at the commission, but she was unable to because of injuries inflicted by another unionized construction worker.

In a later interview, Hounsell downplayed her injuries and said she instigated the fight.

FTQ president Michel Arsenault said his union federation is investigating the incident.

Construction unions insist work stoppages are spontaneous acts by workers, rather than an organized job action imposed by union management.

Charest denounces threats

Premier Jean Charest said threats against his administration would not affect policy decisions.

Thériault said she had received an anonymous message from someone threatening "break both her legs" over the government's proposed bill.

"It's totally unacceptable that they received threats," said Charest.

A sign with a photo of Labour Minister Lise Thériault stands outside a construction site in Montreal. (CBC)"Everyone should denounce that and everyone should be very clear that we will never accept to conduct public policy under threat."

Unionized construction workers are not in a legal position to strike because they have a valid contract with Quebec.

Leaders with the FTQ-Construction union federation are expected to testify at the parliamentary committee Wednesday.

With files from The Canadian Press