The European Parliament requests an opinion from the ECJ on the compatibility of the EU-Mercosur agreement with EU treaties. The focus lies on splitting the agreement into a mixed partnership deal and a trade-only interim agreement under exclusive EU competence. Concerns arise over bypassing national parliaments' ratification rights through the interim agreement. A key issue is the 'rebalancing mechanism' clause, which could challenge EU environmental and consumer protection policies. Additionally, there are fears of weakening the precautionary principle and sanitary standards.