The Maori Party says it is not sure if it can support the Government's current proposal for the ownership of the foreshore and seabed.
Prime Minister John Key has said that putting them in the public domain is the only viable option for discussion.
However, the Iwi Leadership Forum chair, Mark Solomon, says it would be unfair to force this on iwi and hapu, when there are already 12,500 private land titles with seabed and foreshore rights.
The Maori Party says unless further changes can be negotiated, the proposal as it stands would be "a bridge too far".
The party whip, Te Ururoa Flavell, says some issues are too far to bridge not only for the party but also for the Iwi leadership group as well as iwi and hapu.
But he says the party is working hard on the issues.
Mr Flavell says the Maori Party and the Iwi Leadership Forum will meet with Mr Key on Monday morning.
Mr Key has ruled any transfer of private title into the public domain unacceptable. He has also made it clear that without Maori Party support, the law will not change.