Former rangers, traditional owners and conservationists warn Australia's national parks are reaching an environmental tipping point, with funding cuts at both a state and federal level leaving them in poor condition.

$121 million was cut from NSW national parks in the 2016-17 budget, slashing about 100 ranger jobs and in the latest NSW budget, $80 million has been cut from the department overseeing parks.

Federal Environment Minister Sussan Ley said the longer we resist tackling this issue, the more the natural habitat deteriorates, impacting both threatened species and neighbouring farmers.