Italy's Constitutional Court has rejected an appeal by Prime Minister Silvio Berlusconi's government against an upcoming referendum on nuclear power amid widespread public opposition to atomic energy.

The court had already ruled last week that the referendum should go ahead despite a move by the government to impose a temporary moratorium on its plans to return to nuclear energy in the wake of the Japanese nuclear accident.

Italy abandoned nuclear power after a referendum in 1987 following the Chernobyl disaster.

Berlusconi had planned to start building nuclear power stations from 2014 and to produce a quarter of its electricity with atomic energy by 2030.

If the referendum is approved and there is a high turnout, the current temporary ban on re-introducing nuclear power would become definitive.