With the Vic Auditor-General not convinced of the value for money of these PPP I'm increasingly of the opinion that, as someone else has already written, that state governments should drop PPP agreements and do it themselves, even if that means they have to 'carry the can' when things go south.
By dropping the PPP arrangements, the state government would have to fund the whole project and if they encounter issues would need to pay more, wouldn't that just defeat the purpose trying to encourage the competition process during the tendering of the PPP arrangement. That's so they can get the project delivered on a reasonable budget and time-frame.
I believe they just chose the wrong private partner agreement, which mislead them they could do the project cheaper, when they didn't consider any leeway in cost if things went south. Or the private partners interests was to raise more money for their own gain.
I do believe there should be some responsibility on the private partner by promising they can deliver on something at a certain cost and then turning around and say oh no it's the government's fault we went over-budget, even though they didn't actually give any lee-way in their budgeting to account for any mishaps.
Also other than the minor scope changes, I think the cost blowout from the private firm are exaggerated heavily to try to make more profits by asking the state government for more money. They haven't encountered any major problems with the tunnelling, they are also back on schedule, despite being behind schedule before and now it's looking like every detail is confirmed and likely believe I think they can save some extra money by getting the project delivered sooner.