Some Invercargill councillors have raised concerns this week that mayor Tim Shadbolt is struggling to follow what's happening in meetings and is often going on tangents.
Councillor Lesley Soper told Checkpoint that the mayor was often losing his place in the agenda for meetings, and needed to be reminded where they've reached in discussions.
"Several times he's been uncertain about what's been voted on. That's all unfortunate but it is clear for anyone attending the meetings that his performance has flubbed."
Ms Soper maintained this was not an occasional wandering of the mind and that it was happening with increasing frequency.
"This is more than an occasional slipping, this is losing track of the agenda and the role of the chairperson of the meetings. Unfortunately, I think that Tim has ... begun a negative campaign that I think is very unfortunate - attempts to abuse and victimise others don't go down well."
She said that at various points people had asked Tim about what was going on, but the councillor would not go in to detail about what the response was.
"I don't think because of Tim's privacy it's worth taking that line any further, I'm sorry Lisa," Ms Soper told Checkpoint's host Lisa Owen.
"I'm very sad about this situation, Tim is a very colourful character and we all know that... this is beyond that particular aspect of his personality, it's worrying quite a number of people."
But it was just councillors who noticed the behaviour from Mr Shadbolt, Ms Soper said, with members of public commenting too.
"Tim has a long history of great service and has done a lot for Invercargill and we're all aware of that, but increasingly there are members of the public expressing concern about whether or not he's still the person he was when he originally became mayor."
Mr Shadbolt's office has responded to the claims in a statement, rejecting there was anything wrong with him medically.
"I am in optimal health ... Absolutely running for Mayor this year.
He said the criticisms were a part of a politically driven smear campaign against him.
"I do not intend to feed the mudslinging by conducting any more interviews on the matter," Mr Shadbolt's statement read.
However, Ms Soper said she was not standing for mayoralty in the upcoming local body elections, and was only planning to nominate herself as a councillor again.
"There are two councillors who have quite openly indicated and they have both told the mayor that they will be nominating for the mayoralty but to say that there are a bunch of other councillors is just not accurate."
Asked whether the councillors had attempted to go elsewhere to discuss the issues, Ms Soper said: "It's a very unusual situation, Lisa, apart from speaking to the individual, there is really no form or avenue for such matters."
She said at the moment councillors struggled at meetings to make sure they came to effective conclusions under Mr Shadbolt's leadership.
"It's difficult to keep the meetings on track and councillors shouldn't be in the role of having to assist to the extent that we are having to."
