Mexican migrants employed at massive tomato greenhouses in the Leamington area gathered Sunday to complain about what they say are unfair and dangerous working conditions.

The mainly male workers described being forced to spray pesticides without safety protection, living in overcrowded buildings with leaking sewage, long work hours without overtime pay, lack of access to medical care, and not being able to recoup government pay deductions.

The workers said they feared being sent back to Mexico if they dared to complain about the conditions.

They described the issues to a fact-finding mission headed by New Democrat MP Joe Comartin and including student activists, the United Farm Workers of America, and the Canadian Labour Congress.

The United Farm Workers first visited the migrants after reports of a temporary work stoppage. About two dozen workers returned to Mexico once the protest ended, and Comartin says it's not clear whether their return was voluntary.

Workers are typically paid $7 per hour, and work 12-hour days with only one-and-a-half days off per week. Ontario law does not allow agricultural workers to form or join unions.

A municipal councillor said that about 3,000 migrant workers come to Leamington every year to work on the region's tomato farms.