The government's move partly delays the country's nuclear exit decided under former chancellor Angela Merkel after the Fukushima disaster in 2011.
Germany's decision to keep two atomic plants on standby through the winter amid a power crunch has exposed cracks in the government and unleashed criticism from economic and energy experts.
Germany's three remaining nuclear plants were set to be retired at the end of the year. Instead, two of the fleet will be kept in reserve "until mid-April 2023 in case needed", Economy Minister Robert Habeck said on Monday.
But the decision has become a "stress test for the coalition" of Chancellor Olaf Scholz's Social Democrats, Habeck's Greens and the liberal FDP, according to the Sueddeutsche Zeitung daily.
Finance Minister Christian Lindner of the FDP has made no attempts to hide his push for the three plants to remain in use rather than just kept on standby.
"We shouldn't be too picky, but instead do everything that makes our lives easier," he told the Sueddeutsche Zeitung on Monday ahead of the nuclear announcement.
Habeck's decision, which he said was needed to avoid an "extremely unlikely" electricity crisis, partly delays the nuclear exit decided under former chancellor Angela Merkel after the Fukushima disaster in 2011.
A 'necessary' decision
In light of skyrocketing electricity bills, all possible resources needed to be mobilised, according to Veronika Grimm, a member of the government's council of economic advisors.
"The plants should be kept running, not just be on standby," she told daily FAZ on Tuesday, adding that the government should examine extending the lifetime of the plants by five years and even bringing recently closed plants back online.
By contrast, Claudia Kemfert of the economic research institute DIW pointed out that "nuclear plants are not adapted to act as network reserves because they cannot be fired up and shut down easily".
The extension is a sensitive issue for the Greens, which has its roots in Germany's anti-nuclear movement. The decision was "hard to take but necessary as it stands", Green party chief Omid Nouripour told public television.
Habeck stressed on Monday that Germany would not waver from its plan to move on from atomic energy. "New fuel rods will not be put in," he said, adding that the issues this winter "cannot be compared" with the next one.
Habeck's ministry has chartered five floating terminals for the import of liquefied natural gas (LNG) to substitute for Russian supplies, the first of which are scheduled to come online at the end of the year.
At the same time, it has also moved to restart mothballed coal power plants and fill gas storage ahead of the winter to guard against an energy shortfall.