Two mayors from Essex County will be in Ottawa on Thursday.
Leamington Mayor John Paterson and Kingsville Mayor Nelson Santos will join others to lobby MPs to protect food processing plants.
The mayors are worried the federal government will repeal the law that regulates the sizes of packaged foods sold in Canada.
The change could put businesses here at a competitive disadvantage because it would streamline package sizes to match those for sale in the U.S.
"Our local food processors see this as a surprise to them. They weren't part of any round- table discussion about the potential for the deregulation," Santos said. "This is coming right from one side, the influence of the U.S."
Most food products are packaged in larger sizes in Canada, which leaves some concerned that companies would simply move production to the United States instead of retool their plants.
Santos said food processing is big business locally.
"When we look at the number of food processing jobs and the contracts that they provide, whether you're through Sunbrite, Bonduelle, Heinz or Nationwide Canning, we're talking hundreds of jobs, collectively," Santos said. "We're talking thousands and millions of dollars economically and certainly the trade aspect is immeasurable."
Santos expects to meet with Essex MP Jeff Watson about this next week.