Christchurch mayoral candidate Jim Anderton has a comfortable lead over incumbent Bob Parker, a new poll shows.

The independent poll by UMR Research found, in a multi-candidate race, Mr Anderton enjoyed 46 per cent of the vote, Mr Parker 21 per cent, and other candidates 11 per cent between them.

Twenty two per cent were unsure how they would vote.

In a head-to-head contest, Mr Anderton beat Mr Parker by a two-to-one margin -- 61 per cent to 30 per cent.

The survey found that while 63 per cent of Christchurch residents had a positive opinion of Mr Anderton, just 35 per cent have a positive opinion of Mr Parker.

The survey, conducted online from May 27 to June 7, is based on a representative sample of 350 Christchurch residents.