Brussels will delay long-awaited proposals on how to classify nuclear power and natural gas under the EU’s landmark labelling system for green finance, as member states demand looser rules to help counteract the continent’s energy crisis.

EU financial services commissioner Mairead McGuinness told the Financial Times that Brussels would take more time before deciding how to deal with the controversial energy sources under the so-called “taxonomy on sustainable finance” that had been due this autumn.

The debate about how to classify low carbon natural gas and nuclear energy, which produces no CO2 but whose waste byproducts are toxic for the environment, has been supercharged by surging electricity costs that have prompted EU governments into emergency financial action to protect households.