A labour dispute has erupted at Toronto's Pearson International Airport, where members of the cleaning staff have walked off the job.

Three hundred members of the Labourers International Union of North America's Local 183 set up picket lines at Pearson's Terminal 1 on Friday.

They are unhappy with the latest contract offer. LIUNA spokesperson Michael O'Brien told ctvtoronto.ca that the employer is the Hurley Corporation, a subcontractor to the Greater Toronto Airports Authority.

Another 100 union members at Terminal 3 are voting on this offer this afternoon. Results should be known after 4 p.m., he said.

Trish Krale, a spokesperson for the GTAA, said that the workers maintain the washrooms, among other things, in the terminals.

All washrooms will remain open. Hurley Corp. management will perform the workers' duties during the course of the dispute, she said.