A group of caregivers is seeking a judicial review of the health workers' mandate, after losing thousands of dollars in payments.
The workers, who mostly look after family members they live with, had their payments cut because they were not vaccinated against Covid-19.
And although mandates will be removed by next week, the group believed what had happened to them was unlawful.
One of the group, Christchurch woman Jennie, lives with her son, who has a traumatic brain injury.
She was unvaccinated against Covid-19 for reasons she said were personal to her.
She previously received more than $1000 a week for being an in-home carer, but that changed when she became included in the health workers' vaccine mandate last November.
"It was quite a huge financial stress, and we've had to carry out the care regardless of whether we're paid to do it or not, so it did seem a little bit silly that we are living in the same house, carrying out the care anyway, but we are having the funding cut," Jennie said.
After initially leaving in-home carers out of the sector mandate, Ministry of Health officials then argued in-home carers should be treated the same as other workers.
"To me that seems completely ridiculous because we're not the same as the other employees in the sector," she said.
"It's not a public health approach, which is what the vaccine order is meant to be all about."
Jennie is part of a group of five home-based care workers seeking a judicial review of the way the mandate is applied to them.
Wellington lawyer Matthew Hague has filed the challenge with the High Court.
Their inclusion was unjustified and lacked reason, given they mostly lived with the person they cared for, he said.
Despite requests, the group had not been given any health reason for the mandate applying to them.
"We asked the government exactly that. We said, first of all, 'Can you please review this? There's some concerning parts about it. Secondly, if there is a reason can you let us know so we can tell the people it affects'.
"There was zero response to that."
Hague said one of the people involved in the court action had received an Official Information Act reply from the Covid-19 response minister, which spelled out officials' position.
"She says, and this is from Ayesha Verrall, 'The distinction between family and non-family carers was not considered to be relevant to public health and so was removed to ensure that all vulnerable people received the same protection, whether cared for by a family carer or not'.
"It's very clear from that that the purpose of the change is to protect the people being cared for, but it doesn't because they're already living with them."
Disability advocate Jane Carrigan said the inclusion of home-based carers in the mandate covering health workers was mean spirited, considering officials had for years argued they did not have the same rights.
"They don't treat family carers like everyone else, otherwise they would be paid 24/7 and be paid at a much higher rate than the average care support worker, because the level of care they provide is at a much higher level.
"It's cynical."
The ministry initially told RNZ, incorrectly, that people providing care to family members in their own homes were not covered by the mandate.
Requests for clarification have gone unanswered.
RNZ has seen a recent newsletter from an agency that organises in-home care. It said Whaikaha, the Ministry of Disabled People, advised that such workers were no longer subject to the mandate.
However, this week Whaikaha told RNZ that it and other funders of in-home care were working through the results of a recent Employment Court decision that came down on the side of in-home carers.
"When this assessment has been completed we will update our providers and the community."
Jennie said despite the scrapping of mandates, the judicial review still stood.
"I'm hoping that the government will be held to account - that this was an illegal thing to do, and to stop it from perhaps ever happening again should there be another mandate in future health emergencies."
Hague said a hearing date was probably months away.
