Fears the cervical screening change could pose a risk to women's health must be addressed, Labour health spokeswoman Annette King says.
Health Minister Jonathan Coleman's recent announcement that the test will change from liquid-based cytology to human papillomavirus (HPV) screening in 2018 is meeting resistance from women's health advocates and a group led by Dunedin pathologist Peter Fitzgerald.
The move is supposed to cut deaths from the disease by 16% in vaccinated women, and 12% in unvaccinated women.
An editorial in the New Zealand Medical Journal last Friday, whose lead author was Dr Fitzgerald, said the screening change was much too hasty and could lead to over-treatment, strains on the health sector, reduced participation in the programme, and more cancer.
The Federation of Women's Health Councils Aotearoa has also opposed the change.
"Cervical screening in New Zealand does not need another unfortunate experiment. We have come a long way since then,'' federation spokeswoman Barbara Robson said in a press release.
Ms Robson said too much reliance was being placed on a large cohort of women having been vaccinated for HPV, and most women were unvaccinated.
Ms King told the Otago Daily Times she initially supported the change based on information released as part of consultation last year, but the new concerns must be addressed.
"You can't ignore expert advice, and I would want the minister to answer those questions for us.
"If there is now doubt being raised by experts than he needs to answer it, and he needs to tell us which experts he consulted, and what he's based his announcement on.
"If he's got any doubts, then he must re-examine it.
"He can't just put out good news and then hide if there's bad news,'' Ms King said.
Green Party health spokesman Kevin Hague said he did not want to get into a "clinical debate'', but warned against altering the programme without properly assessing the potential problems.
"At this point, I've got no confidence that the ministry has gone through that kind of thorough process.''
Over-treatment of women could lead to serious effects for some patients, Mr Hague said. Dr Coleman released a statement reiterating his support for the new testing regime.
"The advice I've received from the National Screening Unit is that the move to HPV primary testing will save lives.
"Testing for HPV is internationally recognised as a better primary test for cervical screening. As the HPV test is more sensitive, women will only need to be screened once every five years as opposed to three.''
Dr Coleman said the Ministry of Health had "extensively'' consulted the sector on the change, and would continue to work with it to ensure a smooth transition.
