Māori Party president Che Wilson told the Herald the current indecision would cost lives, and allow one of the country's biggest health initiatives to keep widening inequities.
"People are dying. It's not something where we are just talking about as a theory. People are dying, and where there are ways to deal with this we need to be, in a faster way.
"It just shows what is happening throughout this Government - that the Māori MPs don't have a say, about anything."
Bowel Cancer NZ also called for swift action. Spokeswoman Mary Bradley said the delay in dropping the screening age "is costing lives".
"We want to see this happen immediately, as the evidence is there that this will make a huge difference in outcomes for so many Māori bowel cancer patients."
Health workers, researchers and organisations including the Cancer Society and the Māori Medical Practitioners Association also want the screening age dropped. The National Party also supports the change.
Recent board minutes from Counties Manukau DHB indicate a decision to drop the screening age has been made. One reason previously given by the ministry for not doing so was that Māori and Pacific had lower rates of bowel cancer, but data now shows this isn't the case.
"Māori and Pacific bowel cancer results are tracking very close to rates of Europeans," minutes from the November meeting state. "Ministry have therefore agreed to lower the age to 50 years for Māori and Pacific but have not advised a date for when this can start."
However, a ministry spokeswoman said nothing was decided, and there was no change in position since the Herald reported on the issue in November. That story revealed broadcaster and former Silver Fern Jenny-May Clarkson's support for the screening age to be lowered, following her brother's death from the disease at the age of 56.
In it, Dr Jane O'Hallahan, clinical director of the ministry's national screening unit (NSU), said officials were "exploring implementation options" to drop the age for Māori and Pacific people but no decision had been made.
The focus was on the national roll-out while dropping the age was being looked at, she said. That is at the halfway point, with 10 of 20 DHBs offering screening, and expected to be complete by June 2021.
"As has been the case in other countries that have introduced bowel screening, it is important to get the foundation right - to establish the programme within available resources first before any changes to parameters are considered that may increase demand, particularly on colonoscopy services."
Bowel cancer (also called colon, rectal or colorectal) kills more than 1200 New Zealanders every year - more than breast and prostate cancer combined. Early detection is critical to chances of survival, but the disease can be symptomless and others can be reluctant to act when they appear.
For this reason, health authorities piloted a free screening programme in Waitematā DHB from 2012. West and North Aucklanders aged 50 to 74 years were invited to send in faecal testing kits that detect tiny traces of blood that may signal pre- or bowel cancer. If positive, a colonoscopy is done.
Lives were saved and the previous National-led Government pledged almost $200 million to extend it nationally. However, screening is less likely to help Māori and Pacific New Zealanders. That's because the starting age was moved up a decade when the screening pilot went national, to 60.
More than a quarter of bowel cancers strike Pacific New Zealanders between 50 and 59, the latest annual data shows, with one-in-five Māori bowel cancers taking hold in that time.
That compares to about 11 per cent in non-Maori and non-Pacific.
Modelling has indicated that if the age was lowered to 50, then 60 extra bowel cancers a year could be found in Māori, and 25 extra in Pacific New Zealanders.
A previous ministry report investigated dropping the screening age and raised concerns about pressure on DHB colonoscopy services, and the risk of harm from earlier screening such as infection and the possibility of false positives.
However, Wilson said if there was extra demand on services then the private sector should be funded to do colonoscopies. The Māori Party wanted the screening age to eventually drop to 45, in recognition of the fact cancer is more advanced even when it is found in Māori.
Wilson, 44, said he'd had difficulty getting a doctor to refer him for a recent prostate test, even though he was willing to pay for one. That showed the "structural racism" that needed to be countered.
The late Talei Morrison, who started the Smear Your Mea ("smear your thing") campaign that used kapa haka as a way to encourage thousands of women to get tested for cervical cancer, had done more than any official health promotion, Wilson said. Officials needed to back similar champions to increase screening rates in bowel cancer and other areas.
