Ministers in Dublin reacted angrily to the endorsement given by the UK Environment Agency for the £300m scheme.

Joe Jacob, Dublin's minister with responsibility for nuclear safety, said he was "disgusted" that the project had been given the blessing of the UK Government's environment watchdog.

He called on British ministers to overrule the agency statement, which also authorised the continuation of waste discharges into the Irish Sea.

Reprocessing at Sellafield

Mr Jacob said decisions on these two issues should be taken at ministerial level, and that the agency decision should be reversed.

The facility - which has already been built - will create new nuclear fuel from used plutonium, reprocessed at the Sellafield Thorp plant.

The mixed oxide plant could generate more than £100m a year by producing a fuel for sale to overseas nuclear power stations.

'Must be resisted'

The opposition Irish Labour Party's Emmet Stagg called the decision "outrageous".

He said: "This is totally unacceptable, and the battle over the decision is far from over.

"This must be resisted in the strongest possible manner by the Irish Government."