But yesterday the two companies, who own nine nuclear plants, denied they had any plans to cancel their contracts for the new thermal oxide reprocessing plant (Thorp) at Sellafield.
Germany is one of the key foreign customers for British Nuclear Fuels' pounds 1.8bn Thorp plant, now completed but still awaiting approval to start from Her Majesty's Inspectorate of Pollution.
The uncertainty is among several factors which make some observers believe Thorp will never open. If not, it will become one of the nation's most expensive public sector white elephants.
In Germany there is an intense debate about the future of nuclear power, which provides nearly 30 per cent of its electricity. Its use is opposed by environmentalists and many politicians who believe the risks are too high.
The power industry wants the two main parties to have a consensus on future energy policy which gives time to plan ahead - even if it means an end to nuclear power.
Greenpeace claims to have obtained early drafts of a letter from the chairmen of RWE and Veba, two of the six main companies, to the German Chancellor, Helmut Kohl. The first says: 'The reprocessing of burnt-out fuel elements abroad is to be terminated at the earliest possible date.'
The German contracts account for about one-seventh of Thorp's workload in its first 10 years. BNFL said it could not comment as it had not seen the letters.