National's Christopher Luxon on when voters will see final tax plan, and Wayne Brown's Three Waters showdown

National Leader Christopher Luxon says the party's final and costed package on its tax cuts plan will not be released until about a month before the next election, after the pre-election opening of the Government's books.

National has come under pressure to set out more details of its tax policy – including the cost and timing of its tax cuts and how they would be paid for – as National returns fire by calling on the Government to offer up tax cuts itself for workers struggling with the cost of living crunch.

The release of figures showing inflation was sticking higher than expected at 7.2 per cent for the past year led to a renewal of calls from Luxon for the Government to offer tax cuts and cut its spending.

Luxon told the NZ Herald that while elements of its tax plan would be unveiled earlier in election year, National would not release its final fully-costed plan until after the pre-election fiscal update – Treasury's release of the state of the books about a month before an election.

He said National would unwind the list of Labour taxes that it has promised to repeal in its first term in government – which includes the top tax threshold of 39 cents for those on salaries of more than $180,000 - "but of course we want to open up the books and make sure we can phase it and see what we are dealing with."

The plan includes indexing tax thresholds to inflation and scrapping various taxes and levies Labour has introduced, but the full details of the extent and timing of it are a work in progress.

He rejected Labour's claim he would have to cut crucial services to fund it, saying Labour's current spending levels were higher than at any other time – "there's a lot of waste in it. We've never seen this level of cash being sprayed around like it is."

He said the Government was also raking in $32 billion more in tax revenue.

"So the Government, if it was a prudent, responsible government, should be able to give people inflation-adjusted tax relief, as well as deliver better public services."

Finance Minister Grant Robertson has not ruled out offering tax cuts as part of Labour's policy package at the next election, but said no major tax changes were coming this term.

On Tuesday, Robertson threw another salvo at Luxon, calling on him to abandon an "ideological economic plan" - especially the plan to scrap the top tax rate.

He has tried to link National's plans with the United Kingdom, where Prime Minister Liz Truss had to dramatically back down on tax cuts after the impact on the economy – and pointed to comments by former National Party leader Don Brash, who said on RNZ that with high inflation National had to take care with tax cuts if it could not pay for them by spending cuts.

"National's plan could result in mortgage payments going up, inflation worsening, and cuts to essential services for middle and low-income families during a cost-of-living crisis, that's a hefty price to pay so millionaires can better weather the cost-of-living crisis," Robertson said.

Robertson said the Government was now tightening its own belt after the high levels of Covid spending, to bring Government spending back below 30 per cent of GDP again – and spending measures would be "highly targeted."

Luxon said he did not believe Robertson: "He hasn't hit a single forecast in the last five years he's been Finance Minister."

'Entirely appropriate' for Wayne Brown to halt Three Waters spending:

Luxon said he also agreed with Auckland Mayor Wayne Brown's request for WaterCare and Auckland Council to stop work – and spending – on preparing for the Three Waters Reforms, saying it should now wait until after the election.

"I fully agree and entirely support what he is doing. It's entirely appropriate that he stops it."

He said he had met with other new mayors who had told him they were thinking of doing the same.

He said if National won the election it would halt the reforms – and money spent preparing for them was wasted. "They should be saving their money and pushing back. It has not been legislated for yet. They should represent their constituents and there is overwhelming opposition to it. People do not want their assets laundered out of local control to form big entities."

The legislation is currently in a select committee and the Prime Minister has said she was open to making some changes to the reforms after the committee considered the submissions.

He said despite that assurance, the Government had so far not changed its original proposal despite strong opposition to it in consultation. "They're not listening, the public don't want it and [Brown] is right to do that."