THE decision to build a new nuclear power station at Hinkley Point in England is a "significant mistake", SDLP MLA Margaret Ritchie has said.
French energy giant EDF has decided to press ahead with building the new station in Somerset, 150 miles from the Irish coast.
One of the company's 18 board members, Gerard Magnin, resigned just before yesterday's meeting, claiming the £18 billion project was financially "highly risky".
Reports said the board voted by 10-7 in favour of the controversial long-delayed project.
Ms Ritchie, a long-standing opponent of the UK's nuclear energy programme, questioned EDF's decision to go ahead with the power station and said it will have a huge environmental and financial cost.
"By carrying on with plans for the first new nuclear project in 20 years, it is clear that, even with new Prime Minister and Cabinet, the Conservative Government still cares more about seeking prestige from impractical mega-infrastructure projects than they do about the environment or the tax payers who will have to pay higher energy costs for decades," she said.
She raised concerns millions may be spent on a project which could be "unworkable".
"Rather than spending good money after bad on a project unlikely to deliver the benefits promised, we should be investing in diverse sustainable renewable energy that decentralises electricity generation, cuts bills for households and protects our environment from climate change," she said.
An Taisce in the Republic has previously criticised the British government for approving a new nuclear plant at Hinkley Point, saying the station is as close to the Irish coast as it is to London.
The decision to build the new plant was condemned by environmental groups including Friends of the Earth Scotland.
John Sauven, Greenpeace executive director, said: "This deal was more riven with dissension in the EDF board than anyone expected. It's unprecedented division and far closer than predicted.
"Countless experts have warned that for British families this power station will be terrible value for money. This is a bitter pill to swallow for hard up people who have been told that the Government is trying to keep bills down while dealing with energy security and lowering carbon emissions.
"Today's decision doesn't prove the UK is open for business post Brexit - it just shows the Hinkley deal became too big to fail in the eyes of British and French politicians."
However, business groups and the Trades' Union Congress (TUC) welcomed the move.
TUC general secretary Frances O'Grady said the announcement will create "thousands of new jobs and a much-needed economic boost to the region".
"This is exactly the kind of major investment we need following the vote to leave the EU," she said.
"We face serious economic challenges, so projects which bring investment, certainty, and good-quality employment are crucial.
"But this project alone won't be enough. New nuclear capacity should go hand in hand with support for more green tech - like renewables, clean coal and energy efficiency. This can deliver great new jobs - particularly in towns that have lost their heavy industries."
