An economist has told the Waitangi Tribunal that uncertainty over water rights could affect the price the Government can get for shares in energy assets tagged for partial sale.
Ganesh Nana spoke at the tribunal in Lower Hutt, which is hearing urgent claims by the Maori Council and some iwi.
They're seeking to put partial asset sales on hold until Maori claims over fresh water rights and geothermal resources are determined.
Mr Nana said the Crown needed to secure the best price possible for shares in the energy companies - and to do that had to make sure that the price was not unduly affected by uncertainty.
The companies currently relied on water for power generation which was effectively free. If a charge was subsequently placed on that, it would affect profitability.
"If, in the transition to the Mixed Ownership Model, there is uncertainty about the primary costs then there is uncertainty as to its future profitability.
"Therefore there must be uncertainty as to the value of those shares.''
Earlier, an iwi representative speaking at the hearing criticised Prime Minister John Key for comments about water rights and the tribunal, saying she had never been so embarrassed or disgraced by the Crown.
Counsel for Ngati Ruapani, Kathy Ertel, said she had represented Maori in front of the Tribunal for nearly 20 years.
"And in that time I have never known the Crown to be so disrespectful, so misleading and so lacking in good faith as they have in this inquiry.''
She said she regretted having to use such strong language, but it was "an extraordinary situation''.
"We are here talking as a Treaty partner. Never before have I been so embarrassed and disgraced by my Crown - by our Crown - as in the way they have conducted themselves in the matter,'' she said.
Mr Key caused anger among the iwi claimants on the day the tribunal began its hearings by saying the Government was entitled not to pay heed to its recommendations.
His comments have been interpreted as dismissive of the tribunal and have sparked concern from the Maori Pary co-leaders, who are expected to meet with Mr Key on Monday to discuss the issue.
Ms Ertel was also angered by Mr Key's claims that under common law, nobody owned the water.
She likened the water rights issues to fisheries claims, saying in the past nobody had owned fish until they caught them, however the development of the quota system changed that.