The German government wants to raise an extra 2.3 billion euros per year by taxing the profits of nuclear power station operators and introducing an "environmental" tax on domestic air travel, in order to finance its budget deficit.

The biggest utilities, E.ON, RWE, Energie Baden-Wuerttemberg and Vattenfall have campaigned strongly against the nuclear fuel tax and pushed for a tax-deductible fixed charge instead. They have threatened to cut investments and possibly even shut down plants if the tax was implemented.

Germany's 17 nuclear power plants are currently scheduled to be shut down in 2021, under a law passed by the former centre-left Social Democrat-Greens government of Gerhard Schroeder. Opinion polls show a majority of Germans are opposed to extending the use of nuclear power.

In a television interview on August 29, she also said she wanted to give any measure to extend nuclear power a strong legal foundation.

On Saturday Economy Minister Rainer Bruederle said German nuclear power plants should continue operating for a further 12 years beyond their scheduled shutdown date of 2021.

Environment Minister Norbert Roettgen, who has said he wants to limit their extension to eight years, believes there would be very little difference in electricity prices in the future regardless of whether nuclear power is extended by four, 12, 20 or 28 years.

Roettgen said the price difference would be a maximum of 1.8 cents per kilowatt hour long term and that there was no significant relevance in the amount of additional CO2 reduced with longer nuclear use.

"All our relevant goals are achievable," no matter how long nuclear power is extended, Roettgen said. He also warned indirectly that extending nuclear power would reduce the pressure to expand Germany's renewable energy supply.