Mayor Sophie Barker will seek approval from the Dunedin City Council next week to remove Cr Ong as the council's representative on the Otago Settlers Association and the Toitū Otago Settlers Museum board.
She had already stripped from him his role as deputy lead of the technology portfolio.
Last month, Ms Barker wrote to Cr Ong, telling him she was extremely concerned about his behaviour, including his refusal to remove disparaging commentary online about chief executive Sandy Graham.
She also said Cr Ong had been extremely disrespectful to herself, such as talking over her and walking out when she was speaking to him.
If the council approves the mayor's proposed changes, Cr Ong's remuneration will drop from just under $100,000 to almost $84,500.
Nearly all other councillors would have their remuneration edge over $100,000.
Cr John Chambers looks set to pick up the responsibilities of representing the council on the Otago Settlers Association and the Toitū board.
The technology portfolio deputy position would be reconsidered after the by-election in May to replace councillor Jules Radich, who died in January.
Cr Ong has had a troubled start to the term as a new councillor, such as being ejected from a meeting this month and sometimes struggling with the way meetings are run.
He arrived at one meeting with tape over his mouth and soon had to leave, as privileges about attending informal meetings were revoked.
Last year, Cr Ong lodged a complaint against Cr Chambers for "discriminatory remarks", but this was found to be without substance.
His own conduct was then under scrutiny, including an apparent effort to smear a witness whose version of events in the Chambers case did not line up with his own.
Cr Ong criticised the council staff member in an email last month to Ms Graham that he also sent to the Otago Daily Times.
He did not identify the staff member, but the ODT considered it was fairly obvious to whom he was referring.
As the ODT reported last week, independent investigator Steph Dyhrberg found Cr Ong to be in serious breach of the council's code of conduct.
Her report is to be considered by the council at next week's meeting.
If councillors accept her findings, they might then decide upon sanctions, such as asking Cr Ong to apologise or inviting him to consider resigning.
If he were to resign by April 8, a second by-election would not be needed - the existing by-election would instead fill two positions.
Cr Ong has said he has no intention of resigning.
Ms Dyhrberg said in her report Cr Ong breached requirements to "treat all employees with courtesy and respect and avoid publicly criticising any employee".
In any media comment, he was not to "disclose confidential information, criticise, or compromise the impartiality or integrity of staff".
Cr Ong had been on notice several times about the importance of maintaining confidentiality and not exposing council staff to public criticism, Ms Dyhrberg said.
The only rational explanation for copying in ODT reporters to his email to the chief executive was that he was attempting to create a negative perception of the staff member before the journalist covering his complaint about Cr Chambers would find out it had not been upheld, she said.
"I find it more likely than not that Cr Ong acted in retaliation and in attempt to discredit" the staff member, Ms Dyhrberg said.
The staff member's name was redacted in the report.
Cr Ong's email to the chief executive on February 4 was sent 92 minutes after he had received a transcript of what the staff member said about the matter involving Cr Chambers, Ms Dyhrberg said.
This had not corroborated Cr Ong's account, she said.
Ms Dyhrberg found Cr Ong's behaviour posed a serious risk to the reputation and integrity of the council, as well as Cr Ong as an elected member.
She regarded his attempt to discredit the staff member as a witness in a code of conduct process as particularly egregious.
The witness had been apprehensive about participating in the investigation process, Ms Dyhrberg said.
Cr Ong then behaved as had been feared, she said.
"No-one should be victimised or discredited for agreeing to participate in a code of conduct process."
