The New South Wales government has completed just two prosecutions into "unexplained land clearing" since 2017 when the Coalition introduced a much more liberal regime to allow clearing of native vegetation.
Clearing has risen by 73% since the new laws were introduced.
The government has also renamed the category of "unexplained clearing" as "unallocated clearing", but admits it is identical in its scope.
The new figures on prosecutions - with three additional prosecutions now under way - were revealed in answer to questions in the NSW upper house by the independent MP Justin Field.
The NSW government is expected to come under scrutiny this week in budget estimates after new clearing data released in June showed that "unexplained clearing" accounted for 75% of the woody vegetation loss.
Some clearing activities are permitted without permit, such as clearing for fence lines and sheds, or thinning of native vegetation. But much of the activity is suspected to be illegal clearing, particularly in western NSW.
"In June, the government released land-clearing figures which showed over 50,000 hectares of land clearing was unexplained, which means it was either illegal clearing, clearing that occurred under the code but was unable to be demonstrated as having approval, or part of allowable activities on rural land, which includes things like fence lines and sheds," Field said in parliament.
"That is a massive amount of fence lines and sheds being built, if it covers 50,000 hectares of land."
In 2019, 64,000 hectares of clearing was identified as "unexplained"; in 2018 it was 67,500 hectares. In total 180,000 hectares of unexplained clearing has occurred in the past three years of reporting, which represents an area about 650 times the size of the Sydney CBD.
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Field said when he asked repeatedly about unexplained clearing he was told "the government are working on it".
He said he had been told Local Land Services, the Environment Protection Authority and the Environment and Heritage Group were working together on it and "have agreed to focus on future improvements to reduce unexplained clearing" and "new processes" to track it.
Field said this amounted to admitting they were ignoring past clearing.
Mostly the Office of Environment and Heritage uses advisory or warning letters as its preferred approach, with 587 issued. There have been just 13 official cautions, 38 penalty notices and 35 remedial orders.
The NSW opposition has described the situation as unsustainable. Labor's environment spokesperson, Penny Sharpe, promised Labor would use a statutory review of native vegetation laws to consider what would be necessary to stop "skyrocketing" clearing, if elected in March.
Field warned that the Perrottet government's failure to bring land clearing under control threatened the state's pledge to cut greenhouse gas emissions by 50% by 2030 and to net zero by 2050.
A review of the impact of the more liberal laws was planned from the outset if there was evidence of increased land clearing. It has now been postponed and will be part of a five-year review next year.
A spokeperson for the minister for environment, James Griffin pointed to the 273 compliance actions the government had taken during 2020-21 as evidence that the government was acting. These included warning letters, penalty notices, remedial directions, as well as five prosecutions.
She said the Department of Planning and Environment had also implemented an early change monitoring Program, "which allows us to rapidly identify and investigate potentially unauthorised clearing within weeks of its occurrence."
"Since 2019, the NSW Government has secured 600,000 hectares for addition to the national parks estate, and Minister Griffin is working to continue that trend," she said.