The ACT party says the Marine and Coastal Area Takutai Moana Bill will let political connections rather than hard evidence determine who gets customary ownership of the foreshore and seabed.
The party's leader, Rodney Hide, says the bill gives the Attorney-General extraordinary powers to sit down with favoured Maori groups and cut deals away from any scrutiny by courts or Parliament.
Mr Hide told Waatea News that iwi leaders are happy to go along with the new law because they expect better deals from the Attorney-General, Chris Finlayson, than from the courts.
The ACT leader says the simple way to resolve the issue is to repeal the Foreshore and Seabed Act and let Maori pursue their customary rights claims through the courts.
ACT's amendment 'unnecessary, racist'
Meanwhile, Green Party co-leader Metiria Turia is accusing ACT of deliberately damaging race relations in order to boost its electoral changes.
Ms Turei says ACT's proposed amendment that would stop Maori charging for access to beaches if they win customary title is unnecessary and racist.
She told Waatea News ACT is creating doubt and fear in the minds of the public.
If charges for beach access are to be banned, Ms Turei says, then it should apply to the parts of the coast held in private title as well as what ends up in customary ownership.