Potential Mighty River Power shareholders have had plenty to digest and dissect since the prospectus for the part-sale of the state-owned enterprise was released this month. Uppermost in their minds will have been uncertainty over the outcome of negotiations between the owner of the Tiwai Pt aluminium smelter and its electricity supplier, Meridian Energy, and the possible long-term ramifications for power prices.
Now, however, just as the shares go on sale, Labour Party leader David Shearer has lobbed another imponderable into the equation. Labour, he said, would shake up the electricity market when it was next in power.
Inevitably, Mr Shearer will be condemned for the timing of his comment. He will be accused of spitefully seeking to undermine the sale process. But the Labour leader is right to have spelled out this warning to possible investors.
They need to have such information to assess its importance in the overall picture of the share offer. This is particularly the case given that the prospectus is relatively bland. In the case of the Tiwai Pt negotiations, for example, it offers only that a significant reduction to operations at the smelter or even closure "could lead to a sustained reduction in electricity prices in general".
Mr Shearer said Labour's intention was "to make changes to the electricity sector to stem the relentless rise in power bills and to ease future pressure on prices from foreign investors looking to boost profits at the expense of consumers".