BRUSSELS - Environmental groups lodged a lawsuit against the European Commission on Tuesday to challenge its definition of natural gas as a "green" energy source.
In addition, one other non-governmental organisation, Greenpeace, sued the EU executive separately for deciding that nuclear energy was worthy of its sustainable investment label.
The legal actions at the European Court of Justice come a year after the EU established its so-called "taxonomy" -- a classification list -- of energy sources deemed sustainable as it seeks to shift to a carbon-neutral future.
Nuclear power and natural gas were included, considered as "transitional" sources worthy of benefiting from breaks for green financing.
The lawsuit over gas was launched by WWF, ClientEarth, Transport&Environment and the German NGO BUND.
They said in a joint statement that "fossil gas" releases high levels of carbon when burnt, and its extraction and transport contribute to methane emissions.
They called its inclusion in the EU taxonomy "as absurd as it is illegal", arguing that it went against the Paris climate accord and the policies of public financial institutions such as the European Investment Bank.
Greenpeace argued in its lawsuit that the EU was applying a "false label" to nuclear power that could drain green financing from other sources.
Although nuclear power emits no carbon, Greenpeace holds that it represents a danger to the environment.
That view is shared by some EU countries, notably Germany, Austria and Luxembourg, which have also gone to the Court of Justice of the European Union to challenge nuclear's inclusion. - AFP