The watchdog of EU institutions said the Commission had failed to justify the urgency of the measures, citing findings from an inquiry prompted by a complaint by climate and human rights campaigners.
"Taken together the shortcomings amounted to maladministration," Ombudswoman Teresa Anjinho said. "Certain principles of good lawmaking cannot be compromised even for the sake of urgency."
The European Commission did not immediately respond to a request for comment.
The complaint by eight organisations in April said the Commission had proposed a weakening of sustainability rules after private meetings with industry lobbyists, without first consulting the public about the suggested legal changes or assessing their impact.
The organisations said on Thursday that any political agreement should be grounded in evidence and in line with EU climate goals.
"If this cannot be secured, the Commission should withdraw its proposal," their statement said.
(Reuters, November 27, 2025)