Here are the arguments for why did Mexico lose the corn panel in the USMCA.

This Friday, the Mexican and U.S. governments announced that a trade dispute panel ruled that Mexico’s restrictions on genetically modified corn violated the USMCA.

Mexico lose the corn panel

The Panel determined that the Measures are sanitary and phytosanitary (SPS) within the meaning of Article 9.2 of the T-MEC and that the Measures are inconsistent with the following provisions of the USMCA: 

1. Article 9.6.3, because the Measures are not based on relevant international standards, guidelines or recommendations, or on an assessment appropriate to the circumstances of the risk to human, animal or plant life or health. 
2. Article 9.6.8, because Mexico did not carry out a risk assessment taking into account relevant international standards, guidelines and recommendations of relevant international organizations.
3. Article 9.6.7, because Mexico failed to conduct a risk assessment and risk management with respect to the Measures in a documented manner and provide other Parties to the USMCA with an opportunity to comment. 
4. Article 9.6.6(b), because the Measures are not based on relevant scientific principles.
5. Article 9.6.6(a), because the Measures are not applied only to the extent necessary to protect human, animal or plant life or health. 
6. Article 9.6.10, because Mexico did not select SPS measures that are not more trade-restrictive than required to achieve the level of protection it considered adequate. 
7. Article 2.11, because Mexico adopted or maintains a prohibition or restriction on the importation of a good from another Party. 

USMCA ruling

In summary, the Panel recommended that Mexico adjust its measures to comply with its obligations under the USMCA. This is due to the requirements of Chapters 2 and 9 of the agreement.

In addition, the Panel recognized that Mexico is addressing legitimate good faith concerns. However, it suggested that these concerns could be managed through an appropriate risk assessment process. This process should be based on scientific principles. It also stressed the importance of an open dialogue between all parties to the USMCA, which would facilitate finding a constructive long-term solution.

On the other hand, the case began in 2023, when then President Andrés Manuel López Obrador issued a decree. This decree prohibits the use of transgenic corn for human consumption. The measure was taken for public health reasons, with the objective of protecting the population.