Construction workers on residential job sites across Quebec will be back at work on Wednesday, after the provincial homebuilders association reached a tentative agreement this afternoon with its unions

The Association provinciale des constructeurs d'habitations du Québec (APCHQ) confirmed it had reached a settlement which will go to a ratification vote by homebuilders and construction workers across the province in the coming days.

Today is the ninth day of a provincewide strike by construction workers.

Forty-five thousand of them returned to work on roads and major infrastructure projects such as Hydro-Québec's La Romaine site this morning, after the civil engineering and roads sector of the industry reached a tentative deal yesterday.

One key sector still in dispute

That leaves just one sector of the industry — industrial, commercial and institutional construction — still without a tentative deal.

The two sides met with a mediator appointed by the provincial government this afternoon.

Premier Pauline Marois interrupted Fête nationale festivities on Monday to announce that appointment, in a last-ditch attempt to broker a deal in that embattled sector after a three-day negotiating blitz ended without success.

Marois has threatened to introduce back-to-work legislation next week if no deal can be reached by then.

Cost to Quebec $1B a day, opposition charges

Earlier today, the PQ government acknowledged the labour dispute is taking an economic toll on the province.

Both the Coalition Avenir Québec and the official Liberal opposition have called on the government to invoke back-to-work legislation without delay, estimating the costs of the conflict at $1 billion per week.

Labour Minister Agnès Maltais called that estimate "simplistic," saying "a lot of major work has simply been put off for a week."

"We'll evaluate the costs at the end of the strike," Maltais said.