Most voters have not realised how difficult New Zealand's fiscal predicament is, says a think tank boss. 

New Zealand Initiative executive director Oliver Hartwich said the ACT Party's manifesto shows it is the "most radical" about getting government spending to 2017 levels. 

Released yesterday, the manifesto pledged to cut "wasteful spending" by $22 billion over four years, getting debt $12.4b lower by 2031 than currently forecast. 

Hartwich told Ryan Bridge that the plan was different from what other parties were offering. 

Nine years ago, 28.5% of GDP was spent by the Government, but currently the figure sits at nearly 33%, he said. 

"I think that a lot of this extra government spending has not resulted in actually making us feel better, in actually delivering better services for Kiwis, and therefore it is right to ask whether we couldn't achieve better results with lower spending." 

Although that message is landing with some of the electorate, most people do not realise how problematic the fiscal situation is, Hartwich said. 

"We all know that our population is going to age over the coming years, and Treasury told us that by 2065 if we don't change our way, we'll face 200% debt to GDP, which would really mean that we would be bankrupt. These are the levels that we last saw, for example, for Greece in the middle of the Euro crisis." 

He said New Zealand ranks "relatively low" on government spending compared to European nations, but they are "all approaching bankruptcy", he said. 

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