The Prime Minister can be candid to a fault on occasions. He did not need to point out on Monday that the Government could ignore whatever the Waitangi Tribunal might say about the partial sale of power companies just as the tribunal was about to begin hearings on the subject that day. It is well known the tribunal's conclusions are non-binding, but it deserves more respect.
Mr Key, when asked the question, could as easily have said the Government was confident its plans would stand up to scrutiny under legal interpretations of the Treaty. He had reason to be confident.
A few months ago he agreed at the insistence of the Maori Party that the partially privatised companies would continue to be subject to section 9 of the State-owned Enterprises Act that says they must not act in a manner inconsistent with the principles of the Treaty of Waitangi.
That would seem to safeguard any customary or Treaty rights to the use of land, water or other resources that have also been available for electricity generation.
Those rights will apply regardless of who owns the generating assets, which does not include ownership of the water.
The case brought to the tribunal by the Maori Council this week seems to assert not only a Treaty right to the water and riverbeds used by a hydro power plant, but also a right to keep the plant wholly in public ownership. The tribunal may be hard to convince on both counts, particularly the second.
The legally accepted principles of the Treaty were largely laid down by the late Lord Cooke in a case brought by the Maori Council in 1987. The Treaty, he concluded, rested on the premise that each party would act reasonably and in good faith towards the other "within their respective spheres". The Treaty safeguarded Maori rights to land, forests, fisheries and treasures, and gave the Crown the right to govern New Zealand.
The tribunal might need to decide whether the sale of an asset built by the Crown is an action that falls within the rights of government or removes the asset from that "sphere". It is hard to see how the tribunal could find a government had no right to transfer an asset wholly or partly into the private sector if the government considers the transfer to be in the public interest. That is a decision a government of a mixed economy must have the right to make.
But Mr Key has not helped his case, and made the tribunal's task harder, with his careless comment. The tribunal cannot let the remark influence its thinking, though it cannot help its decision, whatever way it goes, being seen as a reaction to the Prime Minister's dismissive attitude to the case.
He would not be first occupant of his office to be surprised by the moral force that a non-binding decision can sometimes bring to bear. Sir Robert Muldoon tried to ignore a tribunal ruling against coastal discharge from one of his Think Big projects but had to back down when the public saw a plain injustice.
Public asset sales have faced even more opposition than Think Big did. If the Government ignores an adverse ruling from the tribunal the successful claimants will have no shortage of allies in their outcry. Already Mr Key's unwise remark has offended the Maori Party and strengthened the claimant's resolve to take the case to the High Court if need be.
No doubt he regretted the comment as soon as it was made. "I'm not saying we would [ignore the tribunal's findings] but we could," he added. He talks too freely for someone in his position, and too much. His open, frank and honest instincts have made him deservedly popular but there are times the public would understand and forgive a little more caution. This was one of those times.