Why was house not sorted in the divorce process?
"The house/assets are entirly different (apparently)!
The ex wife said she was happy to leave the house as he had built it himself and she didnt have interest in taking it over. the main problem being shes happy to be gone but wont part with the house!"
Then the divorce was handled very badly - and before anyone says bloody solicitors, its likely either that this was a d.i.y. divorce or one where the lawyers were not properly briefed. The Irish assets may not be subject to UK jurisdiction but it would be the norm in any divorce in any jurisdiction to seek to negotiate a settlement dealing with all assets worldwide.
Now if Divorce was contested, then its possible that the UK Courts could not rule but then why on earth get a UK Divorce - unless there are substantial UK assets.
So, lots of issues- only OP's partner knows enough to deal with them. Suggest a speedy visit to a good Family Law solicitor in Cork - Rosemary Horgan in Ronan Daly Jermyn is top notch - and no doubt expensive.
mf