Retail, restaurant and agriculture groups met the latest U.S. NAFTA modernization proposal with opposition this week.

The groups are expressing concerns about the reworked trade agreement, saying it could be damaging to U.S. businesses and consumers, Reuters reports.

President Donald Trump signed an executive order calling for the renegotiation of NAFTA within his first week in office and has openly called the agreement the “worst trade deal in history,” blaming it for a loss of American jobs.

But the groups worry the latest propositions could open the door to allow U.S. seasonal produce growers to file anti-dumping cases against Mexico, a measure some fear could lead to retaliation against American producers of avocados, tomatoes and other food typically imported from Mexico, Reuters reports.

The country has already threatened to walk away from renegotiation talks if the U.S. tries to impose tariffs on Mexican products.

According to Reuters, 26 U.S. agriculture groups sent a letter to U.S. Commerce Secretary Wilbur Ross, Trade Representative Robert Lighthizer, Agriculture Secretary Sonny Perdue and Gary Cohn urging American negotiators to drop the fresh produce proposal because there are too many risks associated with it.

NAFTA talks resumed this weekend in Mexico.