Maōri Party co-leader Debbie Ngarewa-Packer's first Members' Bill seeks to ban seabed mining in New Zealand waters and withdraw existing consents.
It is fiercely opposed by mining company Trans-Tasman Resources, which is seeking consents to mine 50 million tonnes a year of iron-sand offshore from Pātea in the South Taranaki Bight.
The New Zealand Supreme Court, meanwhile, is considering whether to uphold an Appeal Court decision which backed a High Court decision declining the consents.
Ngarewa-Packer announced she was putting her Prohibition on Seabed Mining Legislation Amendment Bill in the ballot on March 10. She and her Ngāti Ruanui iwi have been leaders in a campaign against Trans-Tasman's mining proposal, backed by Ngā Rauru, Kiwis Against Seabed Mining, Greenpeace and other iwi and fishing interests.
Allowing Trans-Tasman Resources to mine up to 50 million tonnes of iron-sand a year for 35 years would destroy entire ecosystems and be an environmental disaster, she said.
Her bill would ban mining in New Zealand waters, withdraw previous consents and exploration rights and end the ability to apply for new ones.
It is a member's bill, and will be considered in Parliament if it is drawn from a ballot - or it could be introduced at the next sitting if 61 MPs support it.
The bill was "ideological and alarmist", Trans-Tasman Resources executive chairman Alan Eggers said.
It would deny New Zealand access to a major $1 billion-plus export industry, with 300 permanent jobs.
The black sand off South Taranaki is rich in vanadium and titanium as well as iron - minerals that will be needed for batteries and solar and wind technology in a low-carbon economy.
Seabed mining would only make half the carbon emissions of land-based mineral mining, he said.
New Zealand's Exclusive Economic Zone (EEZ) legislation already balances economic development against environmental protection, Eggers said.
"To ban seabed mining, that has the lowest environmental, ecological and carbon footprint of alternative metal mining operations, completely contradicts the balanced and responsible approach of the EEZ Act and is short sighted," he said.