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, external 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.