Labour Party leader Phil Goff says if re-elected, his party would reverse any National Party decision to remove protection from mining for any protected land.
Mr Goff is touring the Coromandel Peninsula on Wednesday to hear concerns about a Government proposal that would allow mining on parts of the conservation estate.
His first stop was to look at a protective wall built to save Thames Hospital from future mud slides from the Karaka Stream catchment.
The independent Crown Research Institute GNS Science has previously warned that the area is susceptible to the kind of debris flow that partially destroyed the town of Matata.
One woman told Mr Goff people have struggled to get insurance for their properties and she was forbidden from building a fence around her home due to the risk of movement.
Mr Goff says the country's 100% Pure tourism brand is already being damaged by this debate. He says his party's position is unequivocal opposition.