As Belgium becomes the latest European nation to agree to switch off nuclear power, operator Electrabel warned Monday of high costs, environmental fallout and increased dependency on foreign suppliers.

Six parties currently working on a coalition programme that will form the basis of a new Belgian government in the weeks to come, agreed on Sunday to switch off the country's seven nuclear plants from 2015.

But a timetable for shutdown, along with a plan to shift into renewable energy sources, still needs to be worked out, with the government-elect giving itself six months from inauguration day to fine tune how to deliver power to the country's 10 million people.

A front-page cartoon in the Flemish daily De Standaard on Monday showed four pairs of eyes in the dark with one of the blacked out faces saying, "I think Electrabel is trying to make a message heard."

"A decision on the future of nuclear energy is an eminently political one in which Electrabel has no influence," said the operator, a subsidiary of French energy giant GDF-Suez that runs six of the Belgian nuclear plants.

But it added in a statement that the consequences could be dire.

Already a net importer of electricity, Belgium could become increasingly dependent on its neighbours, increase its carbon footprint by replacing nuclear with thermal energy, and be forced to considerably hike the price of electricity for consumers.

"On a question such as this which is fundamental to the national economy, it is essential that clear decisions be taken and communicated," it said.

Operators needed clear guidelines "to programme their activities and investments ... to prepare projects that Belgium will need to ensure security of supply."

Shrugging off nuclear fears following Japan's Fukushima disaster, the Czech Republic has decided to press ahead on nuclear to assure energy independence, while coal-dependent Poland remains determined to make its nuclear debut.

Italy and Switzerland meanwhile have put nuclear power plans on ice, while Germany switched off several reactors in the wake of the Japanese disaster and has since passed legislation to phase out nuclear energy by 2022.

Belgium's seven reactors provide 55 percent of the country's energy needs.

Under the Sunday deal clinched by the country's probable next premier, French-speaking Socialist Elio Di Rupo, the government-to-be would confirm a 2003 law scheduling a shutdown for the seven reactors as they reach 40 years of operational life, between 2015 and 2025.

The seven plants comnbined produce 5.7 GW, a little more than the 5 GW produced by gas and coal plants.

Wind energy totalled 911 MG last year but authorities hope to boost that to 6.3 GW by 2020.

"If we fail to see sufficient alternatives by 2015, we might face a blackout," De Standaard warned.