Christchurch Mayor Bob Parker says the city risks becoming a major political battle if Labour MP Lianne Dalziel becomes mayor.
Ms Dalziel on Wednesday confirmed she will challenge Mr Parker for the mayoralty, which will force a by-election in the Christchurch East electorate.
Mr Parker told Morning Report there is a concern among some people that the city will become a battleground for a bigger national debate if Ms Dalziel is elected.
He said the danger is that next year during the general election, Ms Dalziel's political background will create a diversion away from the rebuild work.
He said people want the rebuild to be centrestage and not be distracted by other political issues.
However, former mayor Garry Moore told the programme that it is time for change as Mr Parker has been unable to lead and unite the city.