The Maori Party is accusing the Act Party of grandstanding over the proposed marine and coastal area bill.
Act is pushing to have a clause added to the bill barring iwi by law from charging for access to the foreshore.
But the Maori Party says iwi have never planned to charge.
Access to beaches and coasts is considered a birthright by most New Zealanders and it is these areas that continue to be divisive.
The Maori Party says fears of charging for access are groundless.
"The point is the people have given access and rights for people to come on. No charge," co-leader Pita Sharples said.
But Act leader Rodney Hide thinks iwi may still charge people to access parts of New Zealand's coastline.
"We want New Zealanders to be under no doubt and so we've asked the government to support an amendment to prohibit the iwi owners from charging," Hide said.
Attorney-General Chris Finlayson said that for the sake of absolute certainty he is prepared to promote an amendment to the bill to ensure free public access.
As a replacement for the foreshore and seabed act, the marine and coastal area bill allows iwi to apply for customary title of specific coastal areas.
But the Maori Party claims that under section 27 free access to all New Zealanders is already guaranteed.
"We're talking about the area of land between high tide and low tide...not the beach at all," Sharples said.
The bill is currently going through parliament and the government hopes it will settle this debate once and for all.