Now, in an unprecedented move the TUV vice-chaiman has publicly apologised for the insult:
The TUV's own website calls the apology a 'correction' in its title, however, and goes on to say:
"Traditional Unionist Voice has apologised for its "childishness" after issuing a statement describing Irish as a "leprechaun language".The statement was issued under the name of TUV vice-chairman Keith Harbinson and condemned the Department of Education for "wasting" money on Irish.
However after being distributed to the media, the press release on the party's website was changed to remove the term.
A spokesman told the BBC the original words were a "childish mistake"."
"TUV would like to clarify that a statement mounted on the party’s website included the wrong headline. This was not the headline agreed with the author of the statement.
TUV apologies for any offence caused."
Apparently, the 'leprechaun' term "had been added to the press release by an employee of the party". That narrows things down quite a bit, as the TUV party staff could probably fit in a Smart car – especially if close personal relatives of Allister himself are excluded.
This blog wondered why the title had been changed so quickly, from 'TUV Blast Leprechaun Language Waste' to 'TUV Blast Irish Language Waste'. One of the possible reasons was 'guilt at being nasty' – and perhaps that was it.
But perhaps also the TUV has realised that playground insults will only get you a certain distance in politics, and they wants to go further.
Could this be the first indication that the TUV is going to try to position itself as a serious grown-up party, rather than just a reactionary thorn in the DUP's side?