Germany is to temporarily halt the phasing-out of two nuclear power plants in an effort to shore up energy security after Russia cut supplies of gas to Europe’s largest economy.

The economy minister, Robert Habeck, announced that the power plants, Neckarwestheim-2 in Baden Württemberg and Isar-2 in Bavaria, are to be kept running longer than planned in order to be used as an emergency reserve until the middle of next year.

Habeck said that after a stress test carried out with four grid operators, considered worst-case scenarios, they had come to the conclusion that “hourly crisis-like situations in the electricity supply system during winter 22/23, while very unlikely, cannot be fully ruled out”.

The decision means Neckarwestheim-2, a 1,310-MW pressurised water reactor (PWR) unit, and Isar-2, a 1,410-MW PWR unit, will remain on standby and fully staffed, but will only generate electricity for the grid if an emergency arises.