Pathologists have written to the government saying the proposed integration of Wellington region laboratory services amounts to privatisation to save money.
The leak of the letter comes as three Wellington-region district health boards - Capital and Coast, Hutt Valley and Wairarapa - are about to announce the next step of a proposal to merge hospital and community medical testing.
In the letter, obtained by Radio New Zealand, 20 pathologists from Wellington and Hutt Valley urge Health Minister Jonathan Coleman to consider the serious harm it may cause.
They say the primary objective is to save money, and while they welcome initiatives to improve lab services, they must be clinically led.
The pathologists say their role has been picking up the pieces of a poorly planned process.
Association of Salaried Medical Specialists executive director Ian Powell said Dr Coleman should be involved.
"His approval is required before any privatisation can occur. Given the state of affairs that's occurred just in recent times and given the pathologists' letter and some other things, then I think that this is becoming too destabilising. I think the minister probably needs to intervene earlier than he would have anticipated having to doing so."
Mr Powell said he expected the DHBs to defer their decision.
Meanwhile, Abano Healthcare announced this morning its 55 percent-owned Aotea Pathology has withdrawn its bid to provide pathology services for the lower North Island beyond October this year.
Aotea has operated in Wellington for more than 80 years.
Abano says it believes the current process would result in a clinically unsound and financially unsustainable outcome with all risk being transferred to the provider.