Mexican workers in Manitoba have voted to de-certify from their union. (CBC)Migrant Mexican farm workers in Manitoba – the first in Canada to join a union – have now voted to decertify.

The farm employees have decided they would rather not be part of the United Food and Commercial Workers union because they can make more money working longer hours, without mandatory overtime pay, which they say caused employers to cut back on their hours.

Heladio Martinez-Perez is a foreman at a farm west of Winnipeg. He said under the collective agreement the workers negotiated two years ago, they could not work more than 70 hours weekly.

"Today, we're gonna start at 6 o'clock and maybe finish at 8. That is a big difference, the union and not the union. We don't need overtime or $1 extra per hour when we can make more hours. That is a good thing for everybody."

Now that they've broken from the union, Martinez-Perez said many of his co-workers ask to work up to 15 or 16 hours a day.

They're sending the money back home to their families in Mexico.

"It's for my daughter's school," said Martinez-Perez. "That's the idea why we are here."

The vote to unionize two years ago was contentious. Some of the workers hired a lawyer, saying they didn't understand what they'd signed. The case went to the Manitoba Labour Board, which upheld the vote. Their first contract came into effect last year giving workers 15 cents an hour over the minimum wage, with a 25 per cent top-up next year.

But while they earned an extra dollar an hour for overtime, they said their employers couldn't afford to pay overtime, so their hours were capped.

Robert Ziegler, president of the United Food and Commercial Workers union local that represents the workers, said they were not paid any overtime prior to their contract. He said the union also protected them against substandard living conditions and provided them with recall benefits and seniority.

Still, Martinez-Perez said the migrant workers were unhappy paying $4 a week in union dues. As soon as they could, they voted to decertify.

"The guys say why do I need to pay more money when I have less hours? It's no fair for us."

More than 18,000 workers from Mexico and the Caribbean are brought to Canada each year to plant and harvest crops.

One expert said the decision to decertify is a setback for migrant workers. David Camfield, who teaches labour studies at the University of Manitoba, said migrant workers in Canada don't have the same rights as other workers who are not in agriculture.

Meanwhile, workers at a farm in British Columbia have also voted to decertify.

But off-shore workers at 13 other farms in Canada have voted to unionize.