In a recent television interview, Mrs Merkel said the stoppages served as a warning about becoming too dependent on single energy sources. Russia supplies Germany with 20 per cent of its oil. "We have to save energy, we have to develop sources of renewable energy," she said. "And of course we have to consider what consequences there will be if we shut down nuclear power stations."
It was the first time the conservative Chancellor has questioned Germany's pledge to phase out the country's 17 nuclear power plants since she became head of a coalition government of conservative Christian Democrats and Social Democrats in 2005.
The anti-nuclear policy was agreed by former chancellor Gerhard Schroder's coalition of Social Democrats and Greens in 2000 and has been a key element in Germany's drive to develop alternative energy sources. The policy has been dismissed by the nuclear lobby and conservatives as "pure ideology".
Social Democrats tried recently to quash any notion that Germany plans to end its anti-nuclear stance. Ulrich Kleiber, the SPD deputy parliamentary leader, said: "Somebody who uses oil supply bottlenecks as an argument in favour of nuclear energy isn't capable of grasping the issue."