Assuming the result would reflect public opinion of a two-to-one margin against any sale, then that's the end of any moral position he claims.
That's why he's pushing hard to get the first power company sold. He's hoping that once one goes, enthusiasm for the petition wanes and the public resign themselves to the inevitable.
But even before he faces that challenge, John Key is already having to do things that make him look compromised.
The National Party leader has had to suck up the embarrassment of having to defend John Banks' dodginess. Last week, the police completed their investigation of Banks' revelation that he concealed his solicitation of Kim Dotcom for cash and put the cheques through his campaign accounts as anonymous. Presumably the police will shortly reveal their decision. If Banks is criminally charged, then Key's job will get even harder.
Even if Banks is put in the dock, our Prime Minister will still be compelled to bat for the defendant. Key built a reputation for putting principle ahead of political expediency when he ruled out even considering a coalition with Winston Peters after the NZ First leader was accused of laundering cash for his campaign.
It is interesting to watch our Prime Minister's face when he is questioned over his Act hypocrisy.
Without the Maori Party votes, his whole asset sales scheme hinges on the support of Act's one vote in Parliament. Without it, Key would be one vote short of a majority.
To keep his single-vote majority, Key has had to sell his integrity. That pre-election cup of tea just gets more expensive.
If this wasn't hassle enough, Maori gave him a real headache this week.
The New Zealand Maori Council, co-chaired by famed jurist Sir Eddie Durie, won a victory this week when the Waitangi Tribunal agreed to consider its bid to halt the sale of the power stations until a claim for water rights was resolved.
The power companies require water - and lots of it - to generate electricity. Obviously, if there is a claim on water ownership then it impacts on their business model. Experts are warning that this new uncertainty causes a real problem that will drive down the sale price.
Key panicked and flippantly sneered that no one owned water. Really? Does he not get a water bill at home?
Then he got carried away, asking who did the tribunal think they were - he'd be making decisions, not them. It made him look like a doofus.
Tariana Turia was forced to posture, sternly requesting a meeting with him. It's instructive that Key declined. Is this the same woman who left the Labour government because she said Clark disrespected Maori?
This time, Turia was relegated to making her protest with a photo opportunity, visiting the tribunal hearings glumly sporting a tino rangatiratanga beany. Frankly, it made her marginalisation more obvious. Key wasn't fussed. Turia arrived and left the event in a Government car, courtesy of him.
Mana leader Hone Harawira saw the political gap, quickly stating many Pakeha who opposed the sales must now realise that the Treaty of Waitangi and the Waitangi Tribunal were the only chance of keeping our power companies in public hands.
Growing protests in the streets; an ever-increasing number of voters signing the anti-privatisation petition; Key's integrity at the mercy of Banks; potential asset buyers fretting; his coalition partner playing up and Harawira winning over Pakeha.
The Prime Minister's normal sunny smile was looking more like a clench this week. For good reason.
