The entire team behind Keep New Zealand Beautiful has resigned, warning the organisation will likely fold in the coming weeks.
The charity - that coined the phrase 'Be a Tidy Kiwi' - has been legislatively mandated to promote litter control since 1979.
Its chief executive Heather Saunderson has now accused the current and former government of bullying and under-funding the organisation.
"My entire team resigned in solidarity with me so it's obviously been a situation where there has been systematic bullying, both at an individual and organisational level," she told RNZ.
Saunderson, who has cancer, penned a now-public letter to the Ministry for the Environment and its minister two weeks ago, asking government representatives to meet with the charity.
"Frankly, I'm a dying woman and Keep New Zealand Beautiful will be a part of my legacy when I'm gone," she wrote.
"I would like to think that the momentum that the team and I have built over the past 15 years will continue and that the next generation of Tidy Kiwis will have the knowledge and skills to manage the environment that they'll inherit."
A spokesperson for the environment minister says the ministry was speaking to the charity's board - and the minister - Penny Simmonds - was across the situation.