The Traditional Unionist Voice has apologised for branding Irish a "leprechaun language".
The party led by former MEP Jim Allister is to hold its annual conference on Saturday as it tries to build-on efforts to draw support from the DUP.
The TUV is a trenchant critic of the DUP decision to share power with Sinn Fein, but had to apologise on Friday after issuing a press release attacking the translation of Stormont government documents into Irish.
The party hit-out at news that Sinn Fein's Minister for Education Caitriona Ruane spent £47,062 on Irish translations.
Its press release on the issue read: "TUV Blast Leprechaun Language Waste."
The TUV's vice chair Keith Harbinson, in whose name the statement was issued, has since apologised and said no offence was intended.
But Alliance MLA Trevor Lunn, who revealed details of the Education Minister's spending by tabling a question at the Assembly, said the TUV blunder was an embarrassment.
"This was a despicable and deeply immature comment. The TUV have shown their true colours during this episode," he said.
"They tried to cynically use the answer to my question and all they managed to do was embarrass themselves."
Mr Allister will use his party conference to underline its opposition to power-sharing and launch its plans for the next General Election.
© Press Association