Go Transit bus service will grind to a halt in fewer than three weeks unless the union representing drivers and other workers can reach a new collective agreement with regional transit agency Metrolinx.

Local 1587 of the Amalgamated Transit Union said Wednesday that it has set Oct. 24 as its strike date.

“We will continue to negotiate,” union local president Ray Doyle told CBC News. “But rest assured that the members have given very strong strike mandates ... and are prepared to walk off the job if negotiated settlements are not reached in their favour.”

The local represents 1,530 workers at Metrolinx, the transit agency for the Greater Toronto Area. That includes 650 Go Transit bus drivers as well as station attendants, service personnel, safety officers and clerical staff.

In a statement, Metrolinx said it remains “optimistic that an agreement will be reached.”

Employees at First Student Canada and Miller Transit in York Region, north of Toronto, are also affected.

The union had wanted to be able to set an earlier strike date, but says it was prevented by Metrolinx’s “cynical” reneging on an earlier agreement about whether Go buses are an essential service.

Among the bargaining issues are salaries. The union says Metrolinx refuses to offer any pay hikes even after management got raises.

Go train service, which is covered by a separate collective agreement with a different union, would not be cancelled by a strike.