EPA Administrator Scott Pruitt’s effort to roll back Obama-era regulations hit a legal roadblock Monday when a federal appeals court ruled the agency illegally delayed a rule to limit methane pollution.

Last month, several environmental groups filed an emergency request to vacate the EPA’s decision to partially halt implementation the methane rule for 90 days while it reconsiders portions of it. The agency, along with intervenors from the oil and gas industry, argued that under a provision in the Clean Air Act, the EPA has the authority to reconsider rules and that the court did not have jurisdiction to review its decision. The court disagreed, ruling 2-1 that the EPA’s administrative stay counts as a final action and is therefore subject to review.