Cheers lads, I've email the CAA asking for clarification quoting the recent amendments to the ANO. If this is possible (and from reading the ANO I assume it is) the IAA stated that they would accept this rating. I quote:
"It is possible to fly Microlight Aeroplanes in Ireland under the privileges of a UK PPL(A) (or any other ICAO Annex 1 compliant aeroplane licence) provided the licence has a valid microlight rating specifically endorsed upon it.".
Cheers,
Ian