Germany today announced plans to become the first major industrialised power to shut down all its nuclear plants in the wake of the disaster in Japan, with a phase-out due to be wrapped up by 2022.

Environment Minister Norbert Roettgen announced the decision by the centre-right coalition, which was prompted by the crisis at Japan's Fukushima plant, in the early hours of this morning, describing it as 'irreversible'.

'After long consultations, there is now an agreement by the coalition to end nuclear energy,' he told reporters after seven hours of negotiations into the small hours at Chancellor Angela Merkel's offices.

'This decision is consistent, decisive and clear,' he added.

Germany has 17 nuclear reactors on its territory, eight of which are currently off the electricity grid. Seven of those offline are the country's oldest nuclear reactors, which the federal government shut down for three months pending a safety probe after the Japanese atomic emergency at Fukushima that began in March.

The eighth is the Kruemmel plant, in northern Germany, which has been mothballed for years because of technical problems.

The decision makes Germany the first major industrial power to announce plans to give up atomic energy entirely. But it also means that the country will have to find the 22% of its electricity needs currently covered by nuclear reactors from another source.

Roettgen insisted there was no danger of blackouts. 'We assure that the electricity supply will be ensured at all times and for all users,' he pledged, but did not provide details.

Roettgen said that none of the eight reactors offline would be reactivated. Six further reactors would be shut down by the end of 2021 and the three most modern would cease operation by the end of 2022.