West Australian Premier Roger Cook said a deal crunched between Tanya Plibersek and the Greens to establish an environment protection agency would have posed a risk to the state’s mining industry and nation’s prosperity.

As some senate crossbenchers disputed the assertion that Ms Plibersek and the Greens had the numbers to pass the Nature Positive bill last week, Mr Cook downplayed his role in Anthony Albanese killing off the push, saying the prime minister did not need his permission.