National have no idea how much the proceeds of asset sales will be. A year ago that nice man Mr Key was talking about $10b. Now Dr English has revised that down to about $6b, but maybe only$5.2b. That's a whopping difference, and if it really is a "best estimate" it is not good enough. In the real world, if the government were a business (and it is not), someone turning up with revenue forecasts like that would be laughed at. And fired. Or, more likely, no one would turn up with such rubbish, because they know they would be laughed at. Or fired.
The debate, a few weeks back, revolved around the extent of the mandate the government held to sell assets. I don't accept the 'partial sale' terminology. The proposal is for asset sales. The proportion sold is a detail and an obfuscation of the reality – the proposal is for asset sales. If we assume there is a mandate of some sort, it is for sales that make sense, in economic terms.
A mandate cannot be claimed if the proceeds cannot be estimated by the vendor's representative. I'd suggest they go back to square one, but with estimates like this, they aren't at square one yet.