I have no reference other than CAP1705, which states:
Those affected
All pilots holding a licence issued by the United Kingdom of Great Britain and Northern Ireland (the UK), in accordance with Commission Regulation (EU) 1178/2011 as amended, operating commercially for a European Operator, whose aircraft are on the register of a EU Member State which is also a member of the European Aviation Safety Agency (EASA).
Is it possible that the UK CAA have got it wrong? Surely not!