The Chancellor, Viktor Klima, warned that the decision would have a decisive influence on Czech hopes of joining the European Union.

The Austrian Government is campaigning for a nuclear-free central Europe, and ministers have expressed concern over the safety of the plant at Temelin, saying it might fall short of the standards demanded by the EU.

Soviet-era technology

Its combination of Soviet-era technology and American-designed safety mechanisms has also been criticised by environmental groups in the Czech republic.

Temelin is more than 10 years behind schedule, and substantially over budget.

President Vaclav Havel described it as a Czech Tower of Babel. He accused the main investor, CEZ, of consistently lying about when the plant would be ready and how much it would cost.

The Czech Government debated the issue for five hours before reaching its decision in the early hours of Thursday.

No consensus

Even then there was no consensus, with 11 ministers supporting Temelin and eight either against or abstaining.

The government insisted that Temelin should not go over budget again, and that it should be ready by September next year.

But it is not clear what will happen if the completion is again delayed or the final cost rises further.