National's Simon Power is complaining that the government has consistently ignored advice from Treasury pushing for more private prisons.
The decision over whether to have private companies profiting from human misery is essentially a political one. It is therefore the domain of elected politicians - not unelected technocrats. If Treasury wants to see the idea implemented, then they should run for election like everybody else.
As for Simon Power, if he genuinely sees the role of government as slavishly following Treasury's advice, then you really wonder why he is in Parliament at all. And if that's what he's going to do if ever elected to Cabinet, I think we'd all be better off if we simply cut out the middle man and had Treasury make the decisions openly. Then at least it would be clear where the accountability lay...