His decision not to seek re-election leaves the mayoral race open for Lianne Dalziel, Labour's earthquake recovery spokeswoman and a Labour MP. Ms Dalziel, MP for Christchurch East since 1999, confirmed last month she would stand against Mr Parker in October's local body elections and would resign as an MP.
Mr Parker, mayor since 2007, said when Ms Dalziel announced her intention he believed he had enough support to retain the job.
In a further development, it was revealed last night that Christchurch City Council's insurance cover for claims under the Building Act has been withdrawn in the wake of the city's consenting crisis. The Government said the council had been advised its professional indemnity and public liability insurer, Riskpool, had withdrawn cover from July 1.
International Accreditation New Zealand, which withdrew the council's ability to issue consents, has raised concerns over technical processing, meaning building consents might not meet the requirements of the building code.
The council voted yesterday to allow a Crown manager to take over the council's building consent functions.
Mr Parker paid tribute to council chief executive Tony Marryatt, who went on indefinite leave this week over the consenting debacle.
"A guy that I've worked alongside for a number of years, for whom I have a lot of respect ... I'm not saying that Tony's perfect in every respect but I also know how hard he's worked ... and all I see that gets directed at him, quite frankly, is a lot of negativity," Mr Parker said.
He also praised all the people he worked with in the aftermath of the Canterbury earthquakes, saying he couldn't have done without them.
"For just one moment in time maybe half a million of us shared something, a shared moment, the terror, the fear, the shock, the pain of that earthquake moment and it knitted us together in a way that I can see beginning to come apart and I think that's a great shame," he said.
Mr Parker said his political baggage from the earthquakes was stopping the city from moving forward.