Next Steps on the USMCA Corn Case: What the Panelists Should Ask

By Karen Hansen-Kuhn

This week the U.S.-Mexico-Canada Agreement (USMCA) dispute over Mexico’s restrictions on genetically modified (GM) corn and glyphosate enters a new phase. A public hearing will be held on June 26 and 27 in Mexico to consider the arguments made by both sides. This will be the first time we’ll hear directly from the panelists who will decide the case and the last scheduled intervention before a preliminary decision is issued this fall. 

As a reminder, the Mexican government announced its plans to transition away from imports of GM corn and the use of glyphosate shortly after President Andrés Manuel López Obrador took office in 2019. These plans were part of a bigger package of reforms intended to strengthen the country’s self-reliance on its food supplies and to move toward agroecological production. Those measures responded to years of concerted efforts by social movements, including successful advocacy efforts and litigation led by the Sin Maíz No Hay País (Without Corn, There Is No Country) campaign to prevent planting of GM corn and protect the country’s cultural heritage and biodiversity.

The initial decree called for phasing out the use of glyphosate and of imports of GM corn by 2024. The revised decree issued in February 2023 continues the eventual phaseout of glyphosate, eliminates the use of GM corn in flour and tortillas for direct human consumption, and calls for the eventual substitution of GM corn for industrial use and animal feed as non-GM corn becomes available.

The U.S. filed a formal dispute under USMCA on August 17, 2023, focused on what the U.S. calls the Tortilla Corn Ban and the Substitution Instruction. The U.S. asserts that the Mexican government’s actions violate Sanitary and Phytosanitary Standards (food and plant safety provisions) in the agreement, saying the decisions were not based on international standards or risk assessment principles and discriminate against U.S. exports. Even though it does not export corn to Mexico, Canada joined the complaint as a third party.

The U.S. and Mexico have each issued detailed complaints and rebuttals amounting to hundreds of pages of information and several hundred informational annexes. Ten non-governmental organizations (including IATP) from Mexico and the U.S. made submissions on the case in April. The Biotechnology Industry Organization, the world’s largest biotech industry advocacy organization, also submitted comments. The panel declined to receive comments from Canadian organizations, even though it did accept a submission by the Canadian government. IATP has posted the government and NGO responses here, along with a series of summary articles and a webinar series by civil society organizations from the three countries. 

Most recently, Mexico filed its formal responses to the second round of the detailed U.S. complaint on June 19, 2024. Incoming Mexican President Claudia Sheinbaum, who will take office on October 1, has indicated her administration’s continued commitment to the restrictions on GM corn and to achieving greater national self-sufficiency in corn production. Now the decision is up to the three-person dispute panel. According to the official timetable (which could be revised), after the hearings this week, the panel will issue a preliminary report in September, with a final decision anticipated in November.

Figure 1. U.S. Corn Exports to Mexico (2014-2023)

The Mexican government offered to conduct joint research with the U.S. on the safety of GM white corn given its importance in the Mexican diet, apparently with no response. The panel will no doubt center many of its questions on the dueling notions that the U.S. standards and the science they’re based on are perfectly fine, versus the Mexican evidence from newer studies of potential harm to human health and the need for a precautionary approach. 

The science around GM corn will be the centerpiece of the debate, but it’s not the only issue. The panelists should also raise questions on other crucial issues, including:

Where's the economic harm?

The U.S. insists that the Mexican rules on GM corn will undermine its exports. In fact, U.S. corn exports to Mexico have increased since the Decree was issued. There was a slight decrease in exports of U.S. white corn in 2022 when Mexico temporarily lifted restrictions on imports of white corn from Brazil due to a drought in Mexico. Since then, the normal tariffs were reinstated, and U.S. white and yellow corn exports have surged to higher levels this year (as indicated in this chart from a U.S. Congressional Research Service report on the dispute).