Firefighters say the country will be less safe on Tuesday because of the sector's Covid-19 vaccination mandate.
Fire and Emergency New Zealand is requiring its 13,000 staff - both professional and volunteers - to have a first dose by then.
New Zealand Professional Firefighters Union national secretary Wattie Watson says a reduction to frontline staff numbers is inevitable and will leave firefighters unable to attend some fires and other incidents.
She spoke to Guyon Espiner.
Fire and Emergency NZ (FENZ) declined invitations to come on the programme. In a statement, FENZ said firefighters work often requires contact with health practitioners, children and students, which means they are covered by the government's vaccine mandate.
"We are securely collecting vaccination status information to comply with the Order and assessing the implications of this mandate for our people, including employment matters, and on the contingency planning we’ve had in place throughout the COVID pandemic. We always have contingency plans in place so we can continue to serve our communities across the country.
"We are working together with our Unions and Associations, and we appreciate the support they are providing our people. Fire and Emergency is made up of people – employees and volunteers – who are dedicated to serving their community. We recognise this is a challenging time for our people and some of them are having to make tough decisions."
FENZ said the organisation had encouraged its people to get vaccinated throughout the pandemic and will continue to do so.
