Nuclear and natural gas energy plants could be counted as “green energy” under controversial EU plans just unveiled.
The European Commission says it has decided that both types of energy can classify as “sustainable investment” if they meet certain targets.
But the move has divided the EU, and been fiercely opposed by some members.
Austria’s chancellor responded to the news by saying “nuclear power is neither green nor sustainable”.
He said he would back his environment minister, Leonore Gewessler, in pursuing legal action at the European Court of Justice if the plans go ahead.
“This decision is wrong,” Ms Gewessler said. “The EU Commission today agreed its greenwashing programme for nuclear energy and [the fossil fuel] natural gas.”
Luxembourg has also said it will join in legal action.
Spain, too, has strongly objected to the idea which was debated for months before being formally proposed on Wednesday.
But those objections are balanced by support from nuclear-using nations such as France. Nuclear energy involves fewer carbon emissions but has different safety concerns and requires disposal of dangerous waste.
Classifying natural gas as “sustainable” also has supporters who argue that some countries which still rely on coal for energy – such as Poland – would benefit from incentives to move to a relatively cleaner supply.
Germany, a powerful country in EU politics, relies heavily on gas in its own energy mix though its environment minister, Steffi Lemke, has criticised the plans.
EU officials were keen to stress that the change was not a requirement for any state or company to invest in gas or nuclear.
But European Commissioner Mairead McGuinness said “we need to use all the tools at our disposal” to reach the climate-neutral target.
Private investment was “key”, she said, and the proposals were “setting out strict conditions to help mobilise finance to support this transition, away from more harmful energy sources like coal”.
Read more at Climate change: EU moves to label nuclear and gas as sustainable despite internal row