BERLIN, March 12 (Reuters) - Chancellor Angela Merkel, whose government has extended the lifespan of Germany's nuclear power plants, called senior cabinet ministers to meet her on Saturday in light of fears of a meltdown in Japan, her spokesman said.
The radiation leak from a damaged nuclear reactor north of Tokyo comes at a difficult time for Merkel, whose conservatives face three state elections in March where worries over nuclear safety could rally her opponents.
Earlier the opposition Social Democrats and Greens seized on the accident in Japan, caused by an earthquake on Friday, to call for a change in Germany's nuclear policy.
"(It shows that) we cannot master nature, nature rules us," said Renate Kuenast, the Greens' parliamentary leader.
The opposition says several German nuclear plants could not withstand a direct hit by an aircraft or an earthquake, although Germany is far less prone to quakes than Japan.
The government's decision last year to keep Germany's 17 nuclear plants running for about 12 years beyond their original shutdown date stirred large-scale protests and weighed on the popularity of Merkel's coalition.
Anti-nuclear protesters will also hold a demonstration on Saturday, with tens of thousands planning to form a 45-km (27 mile) human chain from the city of Stuttgart to an older nuclear power plant that will be kept running longer because of the new policy.
The protest, which had been scheduled before the Japanese quake, is in the state of Baden-Wuerttemberg where Merkel's conservatives risk losing power in elections in two weeks, due partly to rising support for the Greens. Nuclear power is broadly unpopular in Germany.
Foreign Minister Guido Westerwelle, Interior Minister Hans-Peter Friedrich, Environment Minister Norbert Roettgen and an expert on nuclear plant safety will attend Merkel's meeting, government spokesman Steffen Seibert said. (Reporting by Andreas Rinke; Writing by Brian Rohan; Editing by Janet Lawrence)