The Auditor-General has ruled:
In our view, the intent of the Ministry of Housing and Urban Development, and the intent of Ministers, was to establish a new appropriation that would provide authority for the purchase of the land at Ihumātao. However, because the Ministry did not seek the correct approvals, the expenditure was incurred without appropriation and without authority to use Imprest Supply. For these reasons, the payment is unlawful until validated by Parliament.
So the Ihumātao purchase was unlawful, or illegal. This is not a minor thing.
Ministers do not have authority to expend public money unless it obtains an approportion from Parliament. And the money must be spent in line with the appropriation. You can’t for example fund purchase of native trees from Vote Education.
The need for parliamentary approval to tax and spend dates back to the Magna Carta in 1215.
Treasury explicitly warned the Government that their proposed spending may be unlawful. But the Government failed to get an appropriation and spent the money anyway.
If you worked in a private company and spent $30 million without lawful authority, you’d be sacked at a minimum. Of course there will be no accountability here, especially as the PM insists the Government did nothing wrong.