GO Transit says there is a strong possibility that bus drivers and ticket agents could strike after the company and the Amalgamated Transit Union failed to reach a new contract agreement.

"Job actions are a real possibility, but we are waiting for the union to give us notice of their intent," GO Transit chairman Peter Smith said in a press release on Wednesday afternoon.

GO Transit has asked the union for 48 hours' notice before any planned strike so riders would be able to arrange alternative transportation plans.

Later in the day, however, union officials told CTV's Austin Delaney they were not prepared to strike before Christmas.

If workers walk off the job, there will be no GO bus service. The strike won't directly affect GO train operators, but the union has said the workers will set up pickets at GO Transit stations and disrupt service.

GO Transit moves about 165,000 commuters every day, with its 1,800 buses transporting about 30,000 passengers. About 75 per cent of riders travel to and from Toronto.

GO Transit and the union returned to the negotiating table on Wednesday morning after the workers rejected the settlement agreement reached earlier this month.

The employees, who also include maintenance staff and office workers, rejected the deal by a vote of 70 per cent on Tuesday night.

The workers have been without a contract since June 1 and have been in a legal strike position since Dec. 10.

A strike was imminent until the tentative agreement was reached on Dec. 6.

Details of the latest rejected deal were not released, but the two major points of disagreement have been wages and job security.

"There's a lot of things that we're looking at for pensioners," one bus driver told CTV News on Wednesday.

"(GO Transit) is talking about outsourcing, contracting out work, which means we're going to lose jobs and that has to stop, that has stop. There is too much of that going on."

The unionized employees can also been locked out by the company if they choose not to strike.

GO said it cannot offer any more than it already has. No further meetings have been scheduled in the labour dispute.

With a report from CTV Toronto's Austin Delaney