The Government has accused Britain of threatening to renege on a commitment to dramatically reduce Sellafield's radioactive discharges.
The charge was made by the Minister of State for nuclear safety, Mr Joe Jacob, at the opening of a meeting of parties to the OSPAR convention on marine pollution.
Speaking to nuclear experts in Dublin Castle yesterday, Mr Jacob said the UK must ensure it honours the spirit of last July's OSPAR agreement, which involved 15 countries, to reduce marine discharges from nuclear facilities to "close to zero".
Sellafield dominated the opening session, with Mr Jacob expressing reservations about proposals put before the British government by the UK Environment Agency (EA) to ease liquid and gaseous radioactive discharge limits at Sellafield, which include provision for commissioning BNFL's new mixed-oxide (Mox) reprocessing plant.
At the OSPAR ministerial meeting last summer, the British delegation gave a commitment to consider concerns expressed by the Republic and other countries in forthcoming decisions on discharge authorisations for Sellafield.
Mr Jacob told delegates: "In my view, the UK ministers' commitments represented a recognition of the need to achieve dramatic reductions in technetium-99 discharges in the immediate future. I don't regard the proposals from the EA as recognition of this commitment."
The UK government, he added, should reflect seriously on those proposals and ensure its final decision is in line with its OSPAR commitments.
The agreement was a major step forward in protecting the sea environment, but the members of OSPAR's radioactive substance working group attending this week's meeting had an important role in ensuring its implementation.
It was essential, he said, that commitments for reducing and eliminating discharges were met within the agreed time.
This was, he noted, in line with "vigorous campaigns of successive Irish governments" for an end to discharges from Sellafield into the Irish Sea.
Mr Jacob said it was reasonable to say that the tide of public opinion in Europe had moved against nuclear power, and governments were now more acutely aware of the sensitivity of public opinion to nuclear power.
Greenpeace, which has observer status at the meeting, welcomed Mr Jacob's initiative in focusing on Britain and Sellafield. The session was dominated by technical considerations.
A decision on the exact terms of implementation, however, would not be made until later this year when the appropriate ministers would step in, its spokeswoman, Ms Helen Wallace, said.
"In the meantime, we hope the Irish Government keeps up pressure on Britain to end all discharges from Sellafield."