DUP MLA and the Assembly's principal deputy speaker Christopher Stalford has rejected a call to apologise for branding drug addicts "junkies and smackheads".
Deputy Lord Mayor of Belfast Paul McCusker called on Mr Stalford to withdraw the comments, made on social media, in relation to the closure of a needle depository in south Belfast.
The father of a Londonderry woman who died through drug addiction also condemned the comments as “vile”.
Gerald Deehan’s daughter Amanda (34) passed away in January 2019, two days after she was admitted to Altnagelvin Hospital following a relapse in her long battle with addiction.
He told the BBC: “I find it absolutely vile, extremely offensive, that he would use the terminology of junkies and smackheads. These people are victims.
“I would never use (that) terminology. I would never degrade myself by saying that someone is a crackhead or a junkie or this or that.”
The needle exchange at a pharmacy on Botanic Avenue is to close after claims it was attracting anti-social behaviour in the area.
Mr Stalford told the Belfast Telegraph he would not be apologising as his "first and only allegiance is to the people of south Belfast, not drug addicts".
The DUP MLA said that the actions of service users had "made the life of the community very difficult".
He said the service was being used in an "inappropriate way" and he had been inundated with complaints from local residents.
Mr Stalford said that the purpose of the service was for drug users to collect needles and then take them home for use. But he said the needles were instead dumped in public causing a health hazard.
He said that local businesses in the Botanic area had also contacted him to express concern about anti-social behaviour around the service and he was "glad it has ended".
Local residents had staged protests outside the facility in the past, the service is now set to finish at the end of August.
It provides clean needles and syringes to drug users, which has led to groups congregating on Botanic Avenue and the surrounding area.
Discussing the decision on social media South Belfast MLA Mr Stalford said his first concern was "the people who live there, not junkies or smackheads".
Mr Stalford queried if Mr McCusker would support a similar service in the Oldpark area of north Belfast he represents.
"I appreciate people can fall and as a christian I won't pass judgement on anyone," the former Belfast councillor said.
"I don't know how they got to that state. But why should one part of the town pay for it?
"It's exactly the same with where dangerous sex offenders get housed. Inner south Belfast is used as a dump for antisocial elements from all across Northern Ireland."
SDLP councillor Mr McCusker said that Mr Stalford's comments had caused "immense hurt".
“I was deeply shocked to read comments on social media from a senior DUP MLA, who used derogatory language of 'junkies and smackheads' about people suffering from addiction," he said.
“These comments are dangerous and deeply hurtful. They are also devoid of empathy. We should not be judging those who have fallen on hard times or are struggling with addiction. They are someone’s son or daughter. They need our help and compassion, not condemnation.”
"I would urge Christopher Stalford to reflect on them, withdraw them and make a full apology.”