It was policy on the hoof when Labour leader Chris Hipkins and National's Christopher Luxon both promised during Wednesday night's televised leaders' debate that they would lower the age for free bowel cancer screening, if elected on October 14.
The commitment has not been part of either party's policy manifesto until now - and their respective finance spokespeople have been adding some cautious caveats around the pledge.
On RNZ's Morning Report programme today, Labour's Grant Robertson indicated the screening age would have to be lowered in stages.
"The likes of myself, or Nicola if she got the chance to do it, then have to work to see how quickly we could expand it. You'd never do it all at once."
He said Labour had set aside $2.7 billion in funding to meet increasing cost pressures and that included health services.
National has promised to announce its fiscal plan on Friday.
But finance spokesperson Nicola Willis, who appeared with Robertson on Morning Report, agreed that changing the bowel cancer screening age would likely have to be phased in.
"We're going to make sure we've got good buffers in our fiscal plan for the cost pressures and to allow for new initiatives in the future that we may not have anticipated yet that will become pressing needs."
Willis said to implement the promise National would have to consider additional treatment and drug costs, as well as workforce shortages.
On whether the age would be lowered in National's first four years in government - "we would want to examine that initially to look at what all of those implications were before we then funded anything in a future budget", she said.
Bowel Cancer New Zealand chair Stefan Corbett told RNZ's Checkpoint programme New Zealand had the highest rate of bowel cancer in the world, with 1200 people dying every year - and that did not need to be the case.
There is currently universal free screening for bowel cancer in New Zealand for people aged 60 to 74.
Starting screening for the disease at the age of 45 would make "an enormous difference", he said.
"We would like to see a workplan and funding behind that workplan to make sure that this is implemented promptly.
"This is a real problem for New Zealand and it's not necessary; 90 percent of bowel cancers are curable if they're caught early."
Corbett said what he had heard from both leaders in the debate was "a commitment to match the bowel screening age in Australia, which starts from 45".
The leaders were pressed during the debate on whether they would lower the bowel cancer screening age to match that of Australia.
Screening for bowel cancer currently starts at age 50 in Australia, with people able to request screening from the age of 45.
Luxon said it made sense to do it, and went as far to say he would match the age in Australia.
Hipkins also "absolutely" committed to lowering the age for free bowel screening, but was not pushed on a specific age.
Corbett said bowel cancer was the second-highest cause of cancer in New Zealand and it killed more people than prostate cancer and breast cancer combined.
He said in the absence of specific information about the factors that caused it, screening was "the best way to save Kiwi lives" and he expected the next government to implement the lower screening age within its first term.
"We don't want to see any back-pedalling here on a promise that's been made across the aisles; we have waited a long time for the national bowel screening programme to come into play across the country - it's taken too long."
The implementation of bowel screening for Māori and Pacific people from the age 50 - a Budget 2022 announcement - was also taking too long, he said.
"We don't want this to take long as well, we'd like to see the maths on this promptly in their first term."
If National makes it into government, it will have ACT alongside it.
ACT leader David Seymour said the state of the economy meant it was not the time to be throwing around spending promises.
"We need to spend more on infrastructure, teachers, prisons, GPs and defence. But outside of that the government is going to have to be saving money."
Funding cancer services was always a trade-off between the cost of increasing screening or funding more drugs, Seymour said.
"I think those are very difficult and harrowing trade-offs a government has to make. You probably shouldn't fire them out in the course of a debate."
Today, both leaders reconfirmed their commitment to lowering the bowel cancer screening age.
Hipkins said: "I'm not putting a specific age or timeframe on it at the moment because we'd have to work through what that would cost. We'd also have to work through the practical ability to deliver those things."
Luxon said National's health spokesperson Shane Reti already had instructions: "day one in government he's to go to the Ministry of Health and the Treasury to get the business case together for that".
