The Government has pledged to mount a full-scale legal effort next year to oppose the operation of Sellafield's mixed-oxide (MOX) reprocessing plant, following yesterday's ruling by the International Tribunal for the Law of the Sea.
In a preliminary ruling yesterday, the tribunal refused to stop the plant opening on December 20th, because the situation was not sufficiently "urgent".
Crucially, however, it decided that Ireland does have a prima facie case to argue against the plant, which will manufacture new nuclear fuel rods from spent uranium.
The Minister of State for Energy, Mr Joe Jacob, urged the British to delay opening MOX until measures have been agreed to prevent pollution.
The legal battle would continue until "the UK permanently ceases" polluting the Irish Sea, "subjects MOX to proper environmental assessment and co-operates more fully".
A full hearing of the case will go before a five-strong arbitration panel, operating under the UN tribunal, early in the new year, possibly in late February.
The panel's five nominations will have to be agreed between Ireland and Britain, though two will come from each country, with an independent chairman.
The Irish Government will continue with its parallel legal action before the OSPAR Convention, where it claims the British have refused to release sufficient safety information.
Preparations for a European Court of Justice case, which will argue that the MOX plant is economically unviable and therefore illegal under the Euratom Treaty, will be accelerated.
"The Government is determined to buy in all the necessary scientific back-up that is needed to fight this case," said a source close to the Attorney General, Mr Michael McDowell.
Encouraged by yesterday's ruling, the Attorney General said the British had had "to make very important concessions in order to avoid an injunction". Though he would have preferred to stop MOX opening, he said the ruling gave Ireland the right "beyond contradiction" to be involved and consulted about Sellafield issues.
"We have a process whereby they must now engage with us in all of the material matters and must not hold back from us vital information concerning the threat to the Irish Sea," he said. "For the first time, Ireland has an international ruling that accepts that Ireland has an interest in Irish Sea pollution levels."
The British Energy Minister, Mr Brian Wilson, said he was "pleased to note" that the tribunal had not ordered the British government to halt the MOX plant's commissioning.
"The British government will, of course, comply with the decision of the tribunal regarding co-operation and consultations with the Government of Ireland," he said.
