Anna Lo: 'United Ireland' remarks 'insulting', say unionists
20 March 2014 Last updated at 18:49 GMT
The Alliance Party has been accused of abandoning its "middle ground position" after a high-profile member declared her preference for a united Ireland.
Anna Lo described herself as "anti-colonial" and said the partition of Ireland was "artificial".
She was speaking in an interview for the Irish News.
BBC News NI Political Correspondent Martina Purdy reports.