New Zealand First leader Winston Peters said the offer was "divide and rule" tactics. Most Maori opposed the asset sales but another group led by the Maori Council was saying if the sales went ahead it wanted a share of the action, he said.
"Then the Government has said to some iwi 'why join them, why don't you get a share over here that is a percentage that could go to you?'."
The timing of yesterday's announcement was "terribly cynical".
"It's designed to try and corrode support for the Maori Council's action," Mr Peters said.
Mr Solomon, Ngai Tahu's chairman, yesterday told Radio New Zealand National the idea was supported unanimously at a meeting of the Iwi Chairs Forum.
Waikato Tainui chairman Tom Roa, who last month told the Herald iwi were pushing for the deal, welcomed the announcement, although having settled their claim, his iwi would not be eligible.
"The importance for me is that the Crown clearly recognises that it must deal with the iwi who have customary rights over those waterways and I welcome that. I'm unsure of the timing because there are issues around what those customary rights and interests actually are."
Mr Finlayson said Ngati Raukawa had already indicated it was interested in the deal, and he would be surprised if Whanganui, Tuwaretoa and Tuhoe didn't pursue it as well.
The Maori Council said the announcement had no relevance to its claim.
"The shares will be in place of cash. So Maori groups will be no better off then they would be under existing negotiations.
"Those existing negotiations do not recognise Maori proprietary interests in water."
Maori Party MP Te Ururoa Flavell said the main issue was still Maori rights and interests in water, "and that needs to be sorted before we have any other discussion".