(Bloomberg) -- The European Union is likely to unveil on Dec. 22 its plan for how natural-gas and nuclear-energy projects would be classified under its green investment rules.

The long-awaited verdict is dividing the bloc’s 27 member states and some investors, who argue that fossil fuels and nuclear should have no place in the sustainability rulebook, which is designed to help the EU reach climate neutrality by 2050. The proposal by the European Commission would come after a meeting of EU heads of government on Dec. 16, where the so-called taxonomy is expected to be discussed.

The EU’s executive arm is weighing whether the sustainable classification should apply to investments in gas plants that replace coal and emit no more than 270 grams of carbon dioxide equivalent per kilowatt-hour, two people with knowledge of the matter said last month. The projects would have to be finalized by 2030, the people told Bloomberg News.

The design of the EU green investment classification system is closely watched by investors worldwide and could potentially attract billions of euros in private finance to help the green transition. The challenge is to ensure the decision on nuclear and gas gets political support, while avoiding the risk of greenwashing, or overstating the significance of emissions cuts.

A temporary green classification for some investment in gas projects is sought by a group of member states mostly in eastern Europe, led by Poland. The inclusion of some nuclear-energy projects in the taxonomy would help attract private finance in nations like France and the Czech Republic, which plan to rely on atomic power in their transition to net-zero emissions.

©2021 Bloomberg L.P.