Christmas and New Year's leave has been cancelled for military personnel set to cover for striking from non-uniform staff.
The Defence Minister last month invoked the Defence Act, letting uniformed servicemen and woman fill the gaps.
Advocacy group Mission Homefront has written to Judith Collins - saying that's unprecedented and unacceptable.
Co-founder Hayden Ricketts says uniformed staff already give so much.
"You know, those uniformed staff have worked their butts off during the Covid-19 response, they occupied and looked after our country and MIQ and the managed isolation facilities, they've done their best through Cyclone Gabrielle."
LISTEN ABOVE
See omnystudio.com/listener for privacy information.