The government has threatened to retaliate if Austria goes ahead with a legal challenge to the new nuclear power station at Hinkley Point.
The anti-nuclear country claim funding arrangements for Hinkley C breach EU rules on subsidies.
An Austrian MEP said the British Foreign Office was threatening a number of legal moves if they pursue the court action.
The £16 billion project to create a 3,200 MW two reactor nuclear power station was agreed in 2013 by EDF and two Chinese companies.
I don't think that threats by a friendly Government in the European community is something that we would allow to even happen. This is something that is completely out of line.
There are growing fears that the European Commission is delaying the building of a new power station at Hinkley Point in Somerset. It's still to sign off all the building regulations surrounding the project.
Today Labour south west MEP Claire Moody will meet the Commission to try to speed up the process.
The European Commission is expected to announce whether or not it approves plans to build the new Hinkley C power station in Somerset later today.
The commission has been investigating a deal struck between energy company EDF and the government to see if it constitutes illegal state aid.
Britain's first new nuclear plant in a generation is on the verge of getting the go-ahead. The European Commission is said to be about to approve plans for the £16 billion project at Hinkley Point in Somerset. Under the deal, Hinkley C will be built by a French company, EDF energy, which will receive a guaranteed price for its energy for 35 years - at twice the current level.
There has been a protest at Hinkley Point in Somerset today (Thursday 10 April) over plans for a new nuclear power station there. People are angry that the Government has agreed to pay twice the current market price for the electricity the plant will generate.
Meanwhile, Energy and Climate Secretary Ed Davey has given his backing to renewable energy at a tidal power company in South Gloucestershire.
Green Party MP Caroline Lucas will be taking part in a demonstration at Hinkley Point in Somerset today. She and other activists are campaigning against plans for a new nuclear power station at the site because of a range of safety concerns.
She is also angry that the Government has agreed to pay twice the current market price for the electricity the plant will generate.
A month long consultation into Hinkley Point in Somerset has begun this morning by the European Commission. The EU is looking at whether the fixed price the government intends to pay the operator is allowed under European law.
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The financial deal for a new nuclear power station in Somerset is to be investigated by the European Commission, in a move that could delay.
Under the deal, announced by the Prime Minister last month, Hinkley C will be built by a French company which will receive a guaranteed price for its energy for 35 years - at twice the current level. The commission will investigate whether this complies with European rules on state aid.
Greenpeace has dropped its legal challenge to block the new Hinkley C nuclear plant in Somerset.
The campaign group was forced to drop its application for a judicial review after the Government revealed plans for a waste dump, but Greenpeace maintains its view that the radioactive dump will never be built.