The UN tribunal in The Hague hearing Ireland's case against the Sellafield nuclear plant has agreed with the Government's submission that the co-operation given by the UK was not sufficiently "timely or effective".
The tribunal has given an order regarding provisional measures to preserve Ireland's rights in relation to the Irish Sea, pending a final decision in the case in a few months.
The UK must now agree a mechanism for co-operation with Ireland on issues of nuclear safety and the tribunal is seeking a progress report, by September 12th.
The tribunal also said the UK must abide by commitments given to Ireland on June 13th that no decision to authorise further reprocessing at the THORP facility without consulting with Ireland first.
Ireland's case against the UK is based on the 1982 UN convention on the Law of the Sea.
