"Tuwharetoa is pretty pissed off at how Tumu's been treated."
Asked to describe the Kingitanga relationship, the source said: "That's rather sort of strained. The big issue is what does that mean for the traditional relationship of the house of te Heuheu and the house of Potatau?"
The two iwi have the only remaining hereditary paramountcy in the country and have been strongly linked since Potatau Te Wherowhero was chosen as Maori king on the shores of Lake Taupo in 1858. Waikato-Tainui's Kingitanga rangatira is King Tuheitia who told 1000 gathered at Turangawaewae Marae that Maori had always owned water.
As well as unity the hui resolved that a new body be established to set out a framework around proprietary water rights. Further those need to be settled before the sale of shares in state-owned Mighty River Power and before iwi and hapu enter negotiations with the Crown.
Mr Morgan, now a spokesman for King Tuheitia said iwi leaders were "bound" by the decision.
But Sir Tumu responded this week by saying he had been mandated by his iwi to deal directly with the government on the issue.
Tribal heavyweight Napa Otimi warned reporters away from Sir Tumu after his speech at a Crown Shares Plus consultation hui.
Tuwharetoa Maori Trust Board chair John Bishara said even if the tribe entered Crown negotiations he didn't think it would have a bearing its Kingitanga relationship.
"Hell no. It's been going way for way before us and it'll go way beyond us. And it's important we keep that relationship...I don't think this water issue is going to destroy any relationship we've had in the past or in the future."
Waikato-Tainui executive chairman Tom Roa said he perceived the speech as taking a "strong stance" on iwi and hapu rights which recognised their autonomy. In terms of the relationship with Tuwharetoa he said: "When somebody takes a strong stance...there's always going to be a dynamic...those iwi who have always been very strong with the Kingitanga will find a difficulty in the dynamic. I believe there is a respect both ways and from that respect the dynamic can be balanced.
Mr Morgan did not return Herald calls.