In an interview with The Newsletter, John McCallister said the decision warranted a wider discussion betweent the party.
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NI21: Basil McCrea challenges John McCallister on 'dysfunctional' claim

The leader of Northern Ireland newest political party, Basil McCrea, wants an explanation from his deputy for calling NI21 "crazy" and "dysfunctional".

John McCallister used the words in a News Letter interview after his party's decision on Tuesday to switch designation from "unionist" to "other".

Mr McCrea said it was disappointing that Mr McCallister made his disagreement known "in a very public way".

BBC News NI Political Correspondent Martina Purdy reports.