The Government's flagship infrastructure programme, the most expensive in modern history, is in danger of collapse, with Transport Minister Michael Wood now refusing to say whether all the 22 projects promised nearly a year ago will actually be built in the way they were announced.

That puts the fate of $6.8 billion worth of road and rail infrastructure up in the air, and could lead to projects like Auckland's $1.3b Mill Rd, or Wellington's $817m Otaki to North of Levin and $258m Melling Interchange either pared back or dropped entirely.

In January last year, the Government announced the NZ Upgrade Programme, a $12 billion infrastructure package which includes upgrades to schools, hospitals and infrastructure needed to combat climate change.

The centrepiece of the project was $6.8b lavished on transport projects of which $5.3b was to be spent on roads.

The $5.3b cost of those projects was taken from the best estimates of Waka Kotahi-NZTA at the time. After the projects were green lit, Waka Kotahi went back and did a more detailed costing of the roads, a practice known as baselining.

Documents released to Stuff under the Official Information Act show that this took almost a year. Each month, officials provided an update to the Transport Minister Phil Twyford and later Michael Wood.

Some of these briefings warned that the baselines were facing pressures that could push costs significantly higher than those forecast in January 2020. They also warn that there is no contingency fund built into the Upgrade funding for transport, meaning any overruns will force Wood to go back to the Finance Minister for more money.

Wood has finally received advice based on those baselines. When asked by Stuff about the cost pressures mentioned in the OIAs, Wood said that the baselines responded to cost escalation seen across the country post-Covid.

Transport Minister Michael Wood is considering advice on the Upgrade Programme, and is weighing up whether all the projects will be implemented.

'Given the Programme was announced pre-Covid, a baselining exercise has been done to provide more certainty around the scope, cost and schedule of the programme,” says Wood.

When asked specifically whether he could commit to delivering all the projects announced back in January 2020, Wood declined to answer. Instead, he said the Government was weighing up its options.

'Ministers are considering this advice and an announcement will be made in the future,” Wood says.

Stuff has already seen early snippets of the advice provided to Wood, in a wad of heavily redacted papers from the Ministry of Transport. Requests to see the finished baselines have been rebuffed.

One briefing warned of a 'significant increase in [the] volume of property transactions required” by projects in the programme and said that 'unplanned cost increases are an emerging issue”.

Another said that the Wood would be advised in March of this year about the 'total set of choices or trade-offs that may be required to deliver the Programme”.

Another paper said that Crown financed projects, including NZ Upgrade programme had 'incorporated risk that would normally be measured through separate pre-implementation steps”.

- Reporting by Thomas Coughlan/Stuff.