The union representing council staff has called on City of Newcastle leaders to investigate Allan Robinson over "alleged homophobic and sexist slurs".
The United Services Union has written to lord mayor Nuatali Nelmes and council chief executive Jeremy Bath seeking a review in accordance with the NSW council code of conduct into the "alleged appalling behaviour".
Cr Robinson has been under fire after referring to homosexuals as "p--fs" during interviews with the Newcastle Herald and The Guardian and saying a female councillor looked like "Jessie the elephant" during a council debate.
"Why should it be offensive?" he reportedly told The Guardian. "If you're a f---ing p--f, you're a p--f."
Cr Robinson has also used a provocative moniker for Newcastle's gay deputy lord mayor, Declan Clausen, in the council chamber and in media interviews and was the subject of a council investigation in 2015 after he referred to a female councillor as "beefcake".
Gay former rugby league star and actor Ian Roberts, whose partner is a long-time friend of Cr Clausen, joined the debate last weekend when he slammed Cr Robinson's comments as potentially harmful to young people struggling with their sexuality.
The USU said in a media statement on Monday that it was "very concerned about the exposure of council workers to alleged homophobic and sexist slurs".
The NSW council model code of conduct says councillors and staff "must not harass or unlawfully discriminate" on the grounds of gender or homosexuality.
It defines harassment as behaviour that "a) is not wanted by the person b) offends, humiliates or intimidates the person, and c) creates a hostile environment".
The code provides for a range of penalties for misconduct, including suspension, under the Local Government Act.
The USU signed an agreement with Labor candidates, including Cr Nelmes, before the 2017 council election which preserves the number of employees at the council.
But USU organiser Luke Hutchinson said the union action against Cr Robinson, who is part of the council's Independent alliance, was not politically motivated.
"We would take exactly the same line from any councillor if allegations were made of a similar context," he said.
He said he wanted elected officials to be held to the same standards as staff.
"Council is straight on to investigating our members for any alleged breaches of that code, so we're asking for the same type of investigation procedures occur for the elected official in question."
He said the union action was based on feedback from members but not "direct" complaints about Cr Robinson.
"Cr Robinson's comments have been covered by national media and witnessed by our members.
"This has caused distress and ... we've got some concerns from our members that it's pretty offensive to be in council meetings with this type of behaviour ongoing."
Cr Robinson and his three Independent colleagues said in a statement three weeks ago that they "do not endorse hate speech by anyone at anytime".