The Government intends allowing oil and gas exploration in a Maui's dolphin sanctuary, the Greens say.
Details of the latest block offer have been published and MP Kevin Hague says there have been 14 reliable sightings of the endangered dolphins in the area it covers.
Maui's dolphins live only in New Zealand waters and there are estimated to be 55 left.
"The proposed block offer area covers 22 percent of the West Coast North Island marine mammal sanctuary, which was designed to protect Maui's dolphins," Mr Hague said yesterday.
"If National was serious about protecting the critically endangered dolphins it wouldn't be proposing more oil and gas exploration in the part of the ocean where they live."
Mr Hague raised the block offer in Parliament yesterday.
Associate Conservation Minister Nicky Wagner told him sophisticated protection measures were in place for Maui's dolphins.
"We have world's best practice protective regulations in seismic work within the marine mammal sanctuary, and we require compulsory adherence to the seismic code of conduct," she said.
Mr Hague says the Greens would prohibit oil and gas exploration in the sanctuary.