I've seen youtube clips where the Irish performers, be it Luke or whoever, will say this is a Ewan MacColl song or whatever and the comments on the videos will still insist it is Irish. Taking no note of what the singers themselves have said in their intro.

We have a pub session on a Friday night which does have a lot of the crowd pleasers played. I had an English guy the other week ask why we only played Irish songs? We'd done "Dirty Old Town" "Shoals of Herring" and "Leezie Lindsey" :-)