Federal Environment Minister Tony Burke has accused the NSW Government of leaking confidential information in a bid to improve the election chances of their federal counterparts.
A letter sent to the NSW Government in December flagged Burkes decision to approve Whitehaven's Maules Creek open-cut coal mine, near Boggabri.
ABC reported that NSW Resource Minister Chris Hartcher leaked the letter, accusing Burke of delaying the mine’s approval for political gain.
''This announcement is all about kicking off Tony Windsor's re-election campaign and shoring up his support in New England,'' Hartcher said.
Burke said he was disappointed the letter was leaked.
"For the New South Wales Government to take an extraordinary step like they have, misrepresent the situation, effectively lie to the people about the situation, and then in doing so, breach the publication of commercially sensitive information, is an extraordinary thing," he said.
"Barry O'Farrell needs to decide if he is running a government or a PR machine."
Burke said he will no longer send the NSW Government confidential information.
"Because they contain commercially sensitive information, no state government up until today has ever breached that confidence," he said.
"This is probably the last time I'll be able to responsibly share any of that information with [New South Wales], but that's a call they've made."
Whitehaven’s Maules Creek will produce about 60 per cent semi-soft coking coal, and 40 per cent high-quality thermal coal.
The company’s three coal projects will clear most of the 7033 hectare state forest.
Once at full production, Maules Creek will produce 13 million tonnes annually, of which 10.5 million tonnes will be saleable coal.
A final decision on the project is expected in April.