The Labour Party says it will set up an inquiry into a method of extracting underground gas if it is elected as government.
Horizontal hydraulic fracturing, also known as fracking, injects a mix of water, sand and chemicals into wells at extreme pressure to break open long cracks in oil and gas-bearing rocks.
Labour leader Phil Goff says fracking has been banned in some countries and the implications of its use in New Zealand are not known.
Mr Goff says his party would set up an inquiry into fracking as a priority.