SDLP leader Mark Durkan tonight resisted demands to apologise to an Assets Recovery Agency chief threatening to sue him over a deepening police appointment row.
Lawyers acting for Alan McQuillan, the ARA's top man in Belfast, have written to the Foyle MP demanding a retraction over his party's claims that they ensured no officer with an RUC background was selected from a shortlist to become Northern Ireland's chief constable nearly five years ago.
Sir Hugh Orde, then a Scotland Yard deputy assistant commissioner, fended off competition from Mr McQuillan and Chris Albiston to take the top post in May 2002.
Both beaten candidates served as assistant chief constables in the RUC. But with the force's reputation seriously threatened by a collusion scandal involving some officers and loyalist paramilitary killers, the SDLP claimed it played a major role in putting an outsider in charge of policing in Northern Ireland.
A party advertisement heralding its part ignited a political storm in Belfast, with Sir Hugh understood to be incensed.
Unionists on the Policing Board which appointed him were also outraged. The row took a new twist tonight, however when Mr McQuillan - who quit the police to join ARA - confirmed he wants Mr Durkan to say sorry.
"We have asked for this matter to be addressed urgently," he said. "If it's not we will have to consider proceeding for defamation in this case."
Mr McQuillan claimed the SDLP's advertisement linked him to collusion. "I'm going to defend my reputation," he told BBC Radio Ulster. "I have worked long and hard for this community.
"If we can reach some amicable settlement, some sort of apology or retraction we can put this to bed." But Mr Durkan insisted there was no need for contrition.