The Government confirmed last night that it is to take a case to the European Court of Justice following the decision by the British government to expand nuclear reprocessing at Sellafield.
It is also considering offering information and support to British community and environmental groups also planning to fight the expansion. The spokesman said it was believed legal action through the British courts was being considered by a number of these groups.
This option would not be available to non-citizens but could result in speedier redress than going to the European Court, which could take years.
A Government spokesman said the action would be pursued on the basis of alleged infringement of two European Treaties.
The Taoiseach, Mr Ahern, will speak to the British Prime Minister, Mr Blair, today, to raise the Government's objections to the formal approval for the opening of a £460 million plant at the British Nuclear Fuels complex in Cumbria.
Mr Ahern said in the Dβil yesterday that the Government would continue to do everything it could legally and politically to stop the British government from pursuing its proposals.
The legal challenge already underway before the OSPAR Convention, an international environmental body comprising 14 North Atlantic nations would continue, he said.
However the Minister of State for Public Enterprise, Mr Joe Jacob, has already conceded that this action was "largely irrelevant" as a result of the approval for the nuclear plant.
The Government had hoped to get information on the economic reasoning for the plant through the OSPAR action, however the relevant figures contained in documents received so far had been blanked out.
Mr Ahern also said that a "top level" meeting would take place between British and Irish officials today. The proposed plant, he said, had been the subject of "frequent strong exchanges" between the two governments in recent years.
The Labour Party chief whip, Mr Emmet Stagg, condemned the decision to allow the commissioning of the plant. He said Sellafield and its associated nuclear industry represented the single greatest threat to Ireland's safety from nuclear pollution.
He criticised the inaction of the Government in tackling the British government on this issue and "the inability of the Minister responsible, Mr Jacob, to even achieve an understanding of the technicalities and scale of threat posed to Ireland and its people".
Fine Gael's environment spokeswoman, Ms Deirdre Clune, called on the Government to immediately clarify what action it is taking to challenge the British government's decision to give the go-ahead to the plant. "Given the serious safety implications for Ireland, there is an onus on the Taoiseach to state what action, if any, he and his government propose to take to halt this development".
In particular, she said, it must be clarified whether the Government's legal advice conflicts with the British government's assertion that its decision is justified in of European law.