A ruling today from the tribunal which overseas the OSPAR Convention is expected to reject a claim by the Government that Britain is in breach of its international obligations by refusing to provide commercial details regarding the MOX plant at Sellafield.
The case was brought before the OSPAR tribunal in The Hague, a UN Permanent Court of Arbitration.
Britain claimed the information was commercially sensitive, and there should be no requirement to disclose it under the convention which is concerned with the maritime environment.
The tribunal is expected to firstly reject Britain's argument that Ireland's claims are inadmissible, or that the tribunal lacks jurisdiction to deal with Sellafield issues.
However, in the ruling this morning the tribunal is expected to announce a majority decision that the information sought by Ireland does not concern the state of the maritime area.
Therefore Ireland's claim does not fall within Article 9(2) of the OSPAR Convention. As a consequence, Ireland's claim that Britain is in breach of its obligations "does not arise".
The ruling is the second in a week from the Permanent Court of Arbitration on a case involving Ireland and the UK over Sellafield. Last week both sides claimed victory in a different case involving Britain's obligations regarding Sellafield under the UN Law of the Sea.