Wairoa Mayor Craig Little says the Government's farm emissions scheme is a "nail in the coffin" for farmers and potentially his district.
Little also believes it will likely lead to more Hawke's Bay farmland being sold to forestry organisations.
The Government released its He Waka Eke Noa proposal this week for consultation, which is a scheme to make farmers pay for agricultural emissions from 2025.
The plans, a world-first, are aimed at reducing methane emissions to help tackle climate change.
The proposal has been defended by Prime Minister Jacinda Ardern as being largely based on consultation from the farming sector and "enhancing our export brand".