Councillor Phil Mauger and former Canterbury District Health Board chief executive David Meates have thrown their hats in the ring.
They joined Canterbury Mornings with John MacDonald on Newstalk ZB at about 10am.
The debate topics included what should happen with the stadium and if they think the Selwyn and Waimakariri districts should be merged with Christchurch to create a super city.
The contenders were asked what they think is the biggest challenge facing the city at the moment.
Meates said he wants to be mayor and sees a city of so many opportunities.
He said they have lost a lot of trust and confidence and that the council needs to be relevant to the community and that the community is being heard.
Mauger said he is not a politician and not a bureaucrat and wants to regain the trust of the council.
On the stadium, Meates said that his stance on the project has not changed.
He said he has raised a number of questions, in terms of funding sources, and finds it hard to understand why discussions with neighbouring councils and Environment Canterbury is starting at this late stage.
"It can't be a stadium at any cost. We are now at $680 million and we see a stadium increase by another $200 off million into the future.
"I am stunned after 12 years that we actually haven't got a stadium built and quite frankly finding ourselves in this situation."
If a decision is made next week to build the stadium: "That was something, as a community, we will need to get behind and deliver," Meates said.
"I absolutely support a new stadium for Christchurch. That is what has been promised for the city and it has got to be delivered.
Meates said what he has done is raise a number of questions.
"The council has added 5000 seats and that added $50 million to the cost at a time it was obvious there was going to be further significant cost escalation.
"We need to have a stadium that is built and quite frankly if the stadium doesn't proceed it will continue to be a grievance for Christchurch.
"It is those sort of things that this community needs to know and understand.
"That this is what it is committing to, that is the impact it is going to have and these are the operating costs so we have got the certainty as a city to plan going forward."
Mauger said he went and talked to the delivery board and they are guaranteeing that it is a fixed price of $683 million.
"They are dealing with the consortium as we speak and they are 99,99 per cent confident that it is a fixed price," he said.
Meates said: "Having been involved in many large contracts and delivery projects, they are always bloody hard to deliver."
The biggest challenge facing Christchurch according to Mauger is the vulnerable people in Bromley.
"They must be wondering what they have done to deserve this."
He would get the organics processing plant shifted as soon as possible, Mauger said.
According to Meates, the biggest challenge facing Christchurch is Bromley and immediately needs to be sorted and resolved.
On Christchurch becoming a super city, amalgamating the Christchurch, Selwyn and Waimakariri councils, Mauger said: "is bigger always better?"
"Both our neighbors are doing a fantastic job but if it did arise, I would like to see some solid evidence that it worked in Auckland.
"If someone could prove to me that it is a good thing, I would go along with it, but I would say no."
Current mayor Lianne Dalziel announced in July last year she would not be seeking re-election.
Her husband Rob Davidson died in 2020.
At the time, she said she would have needed her late husband by her side to stand again.
"The reality is the one person that I need by my side to do that, my husband Rob who died last year, has gone.
"It is time for a new direction in my life. I don't know where this will lead, but I will always be proud of what has been achieved, and the firm foundation for the future that we have built together."
Dalziel has held the mayoralty for three terms, being first elected in 2013.
