TORONTO — Thousands of summer travellers could see their plans dashed if a lockout of about 500 Greyhound Canada employees goes ahead later this week.

Company spokeswoman Bonnie Bastian confirmed Greyhound told a union representing drivers and maintenance workers they will be locked out if a resolution to contract negotiations is not reached by Thursday.

"We've presented a final offer that we feel is fair and equitable," Bastian said on the phone from Cincinnati.

"On Friday (the union) did vote it down. So if we do not come to a resolution (by) August 12th, we have mentioned to the union that we will have a lockout."

All bus service in Ontario and Quebec would be affected, except for trips from Toronto to Sudbury, Ottawa to Sudbury and all points west.

The lockout would see 490 Greyhound employees grounded, among them 320 drivers. The remaining 170 workers are maintenance and terminal employees.

Ian Laird, President of the Amalgamated Transit Union Local 1415 representing Greyhound operators across Ontario, predicted widespread commuter hassles if Greyhound drivers are locked out.

"We don't think it's a very smart business move especially when we're in the busy season," Laird said.

"You've got all the university kids going back in a couple weeks. Commuter traffic will come to a halt."

Greyhound operators across Ontario and Quebec expect the company will lock out its drivers and use American operators on the cross-border routes as of 12:01 a.m. Thursday.

Laird said 87 per cent of members who voted rejected Greyhound's offer, citing pension issues and driving hours as the key sticking points.

Bastian would not comment on details of the offer, saying it's company policy not to discuss contract details publicly.

"It's between us and the union," she said.

Bastian stressed Greyhound Canada is continuing its operations until Thursday's deadline.

"Until that point, we plan on continuing business as usual -- but we hope to get this matter resolved quickly," said Bastian.