Updated

About 700 ground crew workers have gone on strike at Toronto's airport, the busiest airline hub in Canada.

The unionized workers at Pearson International Airport walked out Thursday night after rejecting a contract offer from Swissport, a company that services 30 airlines at the airport including Sunwing, Air Transat, Air France and British Airways.

The members of Teamsters Local 419 include baggage handlers, cargo handlers, cabin cleaners and other ground staff as well as some employees who tow planes. The union says 95 percent voted against the contract proposal.

The Greater Toronto Airports Authority says it has a contingency plan in the event of a strike but has not provided details.

Air Transat and British Airways say they have plans to avoid flight delays or cancellations.