A class action is being considered over an Auckland Council planning blunder

An Environment Court ruling has left hundreds of homeowners and developers in limbo over building projects in the city's older suburbs, and neighbours having to consider legal action to stop works.

The problems stem from the council's interpretation of new rules in the Unitary Plan for character suburbs.

This has left the council advising about 430 people there is a risk their resource consent could be cancelled by the High Court and to reapply for a new consent under both sets of rules.

Council resource consent manager Ian Smallburn acknowledges it's a very difficult situation for a lot of people, but says the council has a team of 13 staff working case by case to resolve it.