Labour is asking why the Department of Conservation is carrying out pest control on a private island owned by two wealthy individuals during a crucial year for defending biodiversity.
DoC is beginning a pest eradication programme later this month on Great Mercury Island as part of a $1.5 million project which is subsidised by the island's owners Sir Michael Fay and David Richwhite.
Labour conservation spokeswoman Ruth Dyson asked Conservation Minister Nick Smith whether DoC's resources were being diverted to accommodate the department's donors.
Ms Dyson said a privately-owned island should not be a priority when pest control was a "stretched resource". She questioned how protecting the isolated island fitted with the department's larger conservation goals.
DoC is preparing for the worst possum, mice and rat infestation in 20 years as a result of a record beech mast year.