Mr. Declan Fitzpatrick:

It is a British regulatory requirement. Similarly, if you wish to fly an Irish-registered aircraft in Ireland, you must hold an EASA licence, or European licence. In our case, we issue licences to Irish staff. The licence is recognised across Europe.

A number of pilots have found they are unable to fly for UK operators even though they are operating in Ireland and have an Irish licence. It is a very peculiar situation and a consequence of Brexit.