Mayor Tim Shadbolt has been mayor of Invercargill since 1993.

Invercargill Mayor Tim Shadbolt will seek a record eighth consecutive term as mayor, but he may have some competition from current councillors.

Councillors Ian Pottinger and Karen Arnold have refused to rule out mounting a challenge, but SIT chief executive Penny Simmonds shot down rumours that she had her eye on the city's top job.

Pottinger said he gave it some thought over the weekend.

"It's definitely not a no, and it's definitely not a yes. In fact, I was talking about it in the weekend."

Candidates should act early, Pottinger said.

"We've really got to start thinking this now. If you're going to do it, you've got to do it now.

"Our options are open."

Some councillors would bide their time before throwing their hat in the ring, Pottinger said.

"You've got to have a poker face."

Arnold said she was "definitely considering" running for mayor.

"... it's something I am thinking about, yes."

The election was about the city's future, Arnold said.

"We hope we will have some fresh new candidates standing for council," she said,

"One of the significant things for us is this Southland Regional Development Strategy.

"We need people with vision for the future, and we need better leadership from the council."

Simmonds said running for mayor had not entered her mind.

"That's just never entered my mind, and it's not something I ever intended on doing."

Deputy mayor Darren Ludlow said it was too early to tell, but at the moment he wasn't planning on entering the race.

"It's a year away. There's no reason, I'm just quite happy with what I am doing and I'm still deciding whether I'll be standing for council."

Councillor Neil Boniface said he definitely wouldn't be standing for mayor.

Shadbolt - New Zealand's longest-standing mayor - said all he could do was put his best foot forward.

"That decision is made by the people of Invercargill. I think it's a very stable city, Invercargill.

"Not only am I the longest serving mayor, but we have the longest standing city councillor, Neil Boniface, and the longest standing CEO, Richard King."

There was plenty of stake in the upcoming election, Shadbolt said.

"There's going to be a lot of issues that are quite critical. The inner-city upgrade, are we doing it fast enough, are we heading in the right direction, and what's going to happen to the museum.

"I think it's always a great opportunity to debate these issues but instead of it being a talkfest, we get a real outcome."

The 2016 mayoral election will be held on October 8, 2016.