Former minister Shane Jones said the Ministry of Health's hesitancy to hand over data on unvaccinated Māori was evidence that "too much power has been concentrated in the head and hands of Ashley Bloomfield".
He warned Bloomfield had "abdicated his role as a health official by becoming a cultural referee between Whānau Ora and Ngai Tahu".
"It is just astounding the Māori MPs of Labour have allowed this man to pit Māori against each other," Jones said.
Jones said he was concerned Bloomfield had now amassed "power greater than some politicians".
"When you are on such a high horse, you have further to fall and fall he will," he said.
With vaccination rates in Northland, where Jones is based, very low, Jones said he hoped "Dr Bloomfield's team have a plan for army field hospitals, because when the spread hits Tai Tokerau, our tiny hospitals will not cope".
Jones' party, NZ First, was booted from Parliament at the last election, but he was hopeful for a comeback.
"The way in which the Government is currently conducting its agenda - they are making it very easy for NZ First to re-emerge," Jones said.
Jones was particularly concerned the Government was failing to find and vaccinate Māori.
Whānau Ora has sought access to data relating to unvaccinated Māori from the Ministry of Health. It hopes to use that data to increase uptake of the Covid-19 vaccine among Māori.
"The Government has encouraged a new form of Treaty topology.
"In no way was this more evident than in the High Court stoush over Whānau Ora. The fact the health ministry has seen fit to give higher value to Ngāi Tahu's fictional concern with data sovereignty than the lives of Māori in Northland and Auckland is further evidence that too much power has been concentrated in the head and hands of Ashley Bloomfield," Jones said.
The Ministry has so far refused to hand over that data despite a High Court ruling on November 1 which said the Government's health agency should reconsider withholding the information.
Last week, Bloomfield had said that one iwi, Ngāi Tahu, had "an objection and were opposed" to the release of the data - although Ngāi Tahu deputy kaiwhakahaere Matapura Ellison later said the iwi had raised no objection.
Jones said it made no sense for the Ministry of Health and the Government to suspend people's rights with lockdowns and other Covid measures, only to hold its nose when it came to privacy concerns around data sharing.
"The Health Ministry is content for the Bill of Rights to be suspended but when it comes to Tai Tokerau vaccinations they indulge Ngāi Tahu sensitivities on data sovereignty.
Northland DHB is currently 12,000 doses away from getting 90 per cent of its eligible population vaccinated with at least one dose of the Covid-19 vaccine. Of those 12,000 doses 8,548 doses would need to be administered to Māori for Northland's eligible Māori population to hit 90 per cent.
Northland's Māori vaccination date is the lowest, bar one, of all 20 DHBs.
"No consideration trumps the need to vaccinate those people. You will not improve vaccination rates by indulging debates of cultural claptrap. It is gobsmackingly stupid and dopey - Gobsmacking," Jones said.
Jones said he was eyeing a return to Parliament in 2023, but he did not yet know whether his return would be accompanied by NZ First leader Winston Peters.
"I hope so - I haven't had a chance to have an in-depth korero with him," Jones said.
"We all know that Winston is the ultimate comeback kid and he has a thousand per cent support from my family and the many tendrils and branches of the whānau," Jones said.