School bus drivers on the island of Montreal have voted in favour of an unlimited strike, but have yet to set a date.

The vote came on Wednesday, the third strike day this year staged by the 330 drivers who work for Transco. They spent Feb. 28 debating pressure tactics as they attempt to negotiate a new contract, their third strike day this year.

The drivers, who work part-time, earn about $20,000 per year. They are asking for a raise of two per cent per year for three years.

Transco brings about 15,000 students to school at four school boards on the island of Montreal, as well as College Sainte Anne.

An agreement in principle was reached earlier this month, but the drivers rejected the deal.

They've been without a contract since last summer.

In a statement Wednesday, Transco said it offers "the best salaries in the industry in Montreal" and its offer takes into account the “ability of school boards to pay."

It also said that a strike could result in the loss of driving routes and a therefore a loss of jobs for drivers.

The union said it perceives that as a threat.

For now, the drivers seem to have the support of the parents.

“We knew the strike was coming and we’re very supportive of it,” said parent Gren Cowper.

That support is something the drivers are aware is fragile.

“We don't want to inconvenience the parents. We understand that they depend on us to drive their kids to school but if we have to go on unlimited strike, you know, it's just to be heard by the company,” said school bus driver Brenda Frank.

Drivers said parents and school boards will be notified in advance before they walk off the job.