"Rising inflation leads to rising interest rates which makes it even tougher for people to get ahead. And the reality is people aren't being able to get ahead with inflation like this," Luxon said.
The National leader said the Government needed to rein in spending while it could and ensure any spending was high quality.
"You have to get really clear right now about the nice-to-do stuff and the must-do stuff.
"Like you do in your own household budgets, if you don't reshape now, you'll end up making a whole bunch of really tough decisions down the road which will really be about austerity and some really serious cuts. We don't want to see that."
Luxon highlighted the now-axed Auckland Harbour cycle and pedestrian bridge, the price of fuel, taxes, and Kāinga Ora, which he says received extra resources but wasn't delivering better outcomes.
"The problem is we have a constrained economy. We've got our borders shut, we've got massive labour shortages and we've got big spending in government that is actually competing with private sector resources and that is driving into inflation.
"It's just about taking a step back and thinking very dispassionately about actually, is that a good investment or not. I'd put it to you that having an idea that you're going to build an $800 million walking and cycling path then spending $51 million over four months just looking at that project or thinking about it, that's the sort of dumb stuff that needs to be stopped."
'Potent cocktail of supply chain pressures and firm domestic demand'
ANZ, New Zealand's largest bank, has warned the December quarter may not be the peak, and further increases are possible in 2022.
At the end of September, annual inflation was running at 4.9 per cent.
While almost all of the subgroups which make up the theoretical basket of goods that Stats NZ uses to measure inflation rose, the biggest increase was in the household utilities group, which rose by 2 per cent.
This was driven largely by the cost of construction of new dwellings, which rose 4.6 per cent. Coming on the back of similar increases in the previous two quarters, the cost of building new dwellings in New Zealand was 16 per cent higher in 2021 than 2020.
Transport was the second biggest contributor to inflation at the end of 2021, boosted by record petrol prices. Statistics New Zealand said during last year the average price of 91 octane petrol rose 30 per cent, from $1.87 per litre to $2.45.
While some of the drivers of inflation are likely one-off or transitory, high inflation can become self-fulfilling, as workers and businesses seek to recoup the loses by demanding wage increases or passing on higher prices.
Economists have warned the high cost of fuel in particular is likely to push prices up generally, as businesses seek to recoup lost margins from rising transport costs.
Westpac said New Zealand faced a "potent cocktail of supply chain pressures and firm domestic demand" which had raised the core measures of inflation to elevated levels, meaning cost increases could persist.
"This underlying strength in pricing pressures indicates that inflation is likely to remain elevated for at least the next year," Westpac senior economist Satish Ranchhod said.
Although many of the pressures for higher prices are coming from offshore, Thursday's figures also show New Zealand's economy is now generating significant domestic inflation.
Non-tradeable inflation, which roughly means domestic inflation, hit 5.3 per cent in 2021, Statistics New Zealand said, driven by construction, rental and rates.
"Inflation isn't an offshore problem that New Zealand is caught up in," Infometrics economist Brad Olsen said.
"There are real and intense pressures throughout the New Zealand economy which are seeing supply unable to match the demand for goods and services."
Nevertheless, Prime Minister Jacinda Ardern told reporters the problems were largely because of offshore factors.
"New Zealand is alongside every other country that is experiencing this problem of ... high crude oil prices," she said.
National's finance spokesman Simon Bridges said the Government needed to rein in spending to prevent further stoking prices which he said were "a thief in New Zealanders' pockets".
The inflation data is important because it affects how quickly the Reserve Bank of New Zealand could increase the official cash rate (OCR).
The Reserve Bank has a mandate to keep inflation between a band of 1 per cent to 3 per cent.
Already the central bank has begun raising the OCR in a bid to cool the economy, with small hikes in October and November taking the cash rate to 0.75 per cent.
That has already had a flow-on effect to borrowing rates which have risen sharply since June in anticipation of increases to the cash rate. Economists say more is needed, however, even though the housing market is showing signs of cooling.
ANZ last week said it expected the OCR to be lifted in steady 25 basis point steps to a peak of 3 per cent by April 2023, having previously a forecast peak of 2 per cent.
That saw wholesale interest rates spike. By Friday the two-year swap rate was at 2.34 per cent - up 15 basis points over the week.
