Anderton announced in May 2010 that he would contest the Christchurch mayoralty that October. He initially said that if elected to the mayoralty he would not give up his seat in Parliament because he didn't want to cause an expensive by-election. However, following the 2010 Canterbury earthquake Anderton announced he would stand down as MP for Wigram if elected mayor so he could fully focus on rebuilding the city. Anderton was leading the polls until the earthquake hit. He lost the election, taking 40.6% of the vote to incumbent mayor Bob Parker's 53.7% of the vote, with the rest of the vote split amongst numerous minor candidates.