The Taoiseach has said he intends to speak to the British Prime Minister about the expansion of nuclear reprocessing at Sellafield.

Mr Ahern, responding to the Fine Gael leader, Mr Michael Noonan, said: "I hope to speak to Prime Minister Blair today. I will certainly speak to him within the next 24 hours."

He added that a high-level meeting between British and Irish officials was scheduled for today to discuss the matter.

The expansion was an entirely unreasonable position on the part of the British, who had not listened to the Irish case for nine or 10 years, said the Taoiseach.

"The EURATOM Treaty allows Ireland to make a case concerning the justification of the plant, with specific reference to the withholding of information on the cost of the plant, the fact that its capital cost was excluded from the economic case, and the violation of the obligation to subject the plant to proper environmental assessment," he said.

"We can fight the decision on these grounds, which, admittedly, are perhaps the grounds under which we have to fight it. The Government believes it has a sustainable case under EU law."

Mr Noonan said that Mr Blair had told the House of Commons that there was incontrovertible evidence that the attacks on the US were organised by Islamic militant Osama bin Laden's group.

"Mr Blair's declaration of this fact is, in all probability, the first step in declaring war against Afghanistan, and possibly other countries within the next few days," said Mr Noonan.

"In view of the ease with which a ship on the high seas carrying plutonium rods may be deemed a terrorist target, will the Taoiseach, as an interim measure, request the British Government today to defer its plans to construct the MOX plant at Sellafield until a peaceful world order has been established, whenever that may be?"

Mr Noonan said the four-year campaign to close Sellafield had been an abject failure.

The Labour leader, Mr Ruair∅ Quinn, claimed that an inter-departmental committee set up to deal with the issue met infrequently and had been "effectively mothballed".

Mr Ahern insisted that the current Government and previous governments had done everything they could on every front, legally and politically, to stop the British Government from pursuing its proposals for Sellafield.

The proposed plant had been the subject of frequently strong exchanges between the two governments over the past four years, and long before that.

"The UK's view that the manufacture of MOX fuel is justified does not accord with the Irish view that the economic case has not been made in accordance with the requirements of EU law," said Mr Ahern.

Later, replying to special notice questions, the Minister of State for Public Enterprise, Mr Joe Jacob, said he was dismayed and angered by the news.

"What is particularly worrying about the decision is that it comes at a time when one would have expected countries with nuclear installations to consider the full implications of the recent atrocity in New York and Washington and the very real threat to safety and securing of such facilities," said Mr Jacob.

"I have to say that I find this decision by the UK Government incomprehensible."

He was advised, he said, that it would be some time before the plant was fully commissioned.

"In the meantime, and in tandem with the continuing progress of the action under OSPAR, the Irish Government will immediately press ahead with a view to finalising consideration of the further legal options under both EU and UN law with the ultimate aim of having the UK decision on MOX overturned.

"The process is already well advanced, and based on the best legal advice, both from our national and UK advisers, the optimum path for proceeding from here will be determined and pursued," said Mr Jacob.