The National party has stepped outside of the drug procurement process when they promised to fund 13 new cancer drugs, the former chair of Pharmac says.
Last month the government backtracked on National's campaign promise to put $280 million towards funding the drugs.
Former senior Labour minister Steve Maharey chaired Pharmac for the previous five years - stepping down at the end of 2023.
Speaking to RNZ Tuesday Maharey said some drugs on the list were no longer current while others had been previously declined or had never had applications for funding through the proper channels.
"They realised that they've caused themselves some pretty serious problems here. They've said they couldn't do it because they can't afford it, obviously they can because they've got money for other priorities they could've put into this. So they are in a dilemma now of how do you actually do this without causing more problems," Maharey said.
Pharmac would assess a medicine once an application for funding was made - typically by a pharmaceutical company - and then negotiate a price to make the drug available to the public once funding was granted by the government, he said.
"At the moment what they've done is to say 'we're not doing that any more, we're going to take these 13 medicines that the cancer control agency suggested' which by now is out of date and what the government's saying is that 'we're going to ignore all the processes, we're going to ignore all the assessments we're simply going to fund them'."
Maharey said the government could simply order Pharmac or another health agency to purchase the medicines - but doing so would hamper the agency's ability to negotiate a competitive price with the imperative to fund them public knowledge - or they could engage in the Pharmac process allowing them to work through a list of relevant medications, including the 13 drugs.
Doing so would incur extra costs as other drugs would fall within Pharmac's list of relevant options and need to be negotiated alongside the list of the 13 promised drugs, he said.
The country was "not one of the most generous in the world for what we put into medicines" and as a result many drugs funded in other countries remain unavailable in New Zealand.
"I suspect most New Zealanders would say we should be paying more into medicines because people are constantly in a position where they can't access medicines and they need to."
The scenario put the effective functioning of the Pharmac model at risk, he said.
"Why wouldn't every lobby group that's involved with heart or kidneys - or parts of the cancer system that are not addressed by these 13 drugs - all turn up and say 'lets forget the Pharmac model, if you're prepared to pay for this directly why don't you pay directly for everybody?'"
He questioned why the government sought to step beyond the model and do things differently when he felt the existing model simply needed greater funding to be effective.