Comhaltas of course include English language native Irish songs in their activities, as I said in my posting.
They choose to ignore the Anglo/Scots/Irish ones, i.e. those which probably originated in Britain, but ended up in the Irish repertoire.
One of the best anthologies of Irish singing ever produced was CCEs 'Traditional Songs and Singers' from the recordings made by Seamus MacMathúna The singers on the album include Paddy Tunney, Geordie Hanna, Liam Weldon, Elizabeth Cronin, Paddy Berry, Des O Haloran, The Keane Sisters... etc.
All but two songs are in English (from the Irish repertoire), 1 is in Irish and the other is a macaronic (dual language) song
Jim Carroll