Members of the European Parliament (MEPs) supported an objection on Tuesday to the classification of nuclear and gas energy as environmentally sustainable activities under the EU Taxonomy. The objection was supported by a majority of MEPs from the Economic and Monetary Affairs and the Environment, Public Health and Food Safety Committees in a 76 to 64 vote, raising the prospect that nuclear and gas could potentially be left out of the EU’s green investment classification system.

The EU Taxonomy is part of the EU Action Plan on Sustainable Finance, established by the EU Technical Expert Group on Sustainable Finance (EU TEG). The taxonomy is a classification system enabling the categorization of economic activities that play key roles in contributing to the EU’s key environmental objectives, starting with climate change mitigation and climate change adaptation.

The regulation went into effect at the beginning of this year, with the status of nuclear and gas remaining initially undetermined, until the Commission published a Delegated Act, proposing criteria and disclosure rules for their inclusion in the Taxonomy. The publication of the Act moved the proposal on to the European Council Parliament and Council for formal adoption unless objected to by a qualified majority (72% of member states) in the Council or a majority (50%+) in Parliament.

While gas and nuclear energy are often viewed as transition energy sources that will be required to facilitate the shift from fossil-based power to a greener energy system, the European Commission’s own sustainable finance advisory group the EU Platform on Sustainable Finance recently opposed classifying them as green activities under the Taxonomy, warning that they don’t fit the strict criteria of the Taxonomy’s framework for transitional activities, which include making a substantial contribution to mitigation objectives and ensuring no significant harm.

The Commission’s move to include nuclear and gas in the Taxonomy met strong resistance from some member countries, with Austria and Luxembourg announcing that they would take legal action against the proposal, and Germany stating that it would vote against it.

In a statement announcing the committees’ vote on Tuesday, the MEPs stated that while they recognize the role of nuclear and gas in providing a stable energy supply through the transition to a sustainable economy, their inclusion in the Taxonomy “do not respect the criteria for environmentally sustainable economic activities.”

The resolution also included a request for future delegated acts to undergo public consultations and impact assessments, given the potential for significant economic, environmental and social impacts.

The vote on the resolution is scheduled for early July, and the Parliament and Council have until July 11 to decide whether to veto the Commission’s proposal.