Last night Planning Minister Brad Hazzard announced a 60-day moratorium on new coal and coal seam gas exploration projects as part of what he called a "rigorous strategic approach" to land use planning.

Just hours earlier, Cockatoo Coal said it had already started on a drilling program that involves 30 sites over 16 weeks after being given government approval earlier than expected.

Mr Hazzard's new regime includes, as transitional arrangements, an immediate 60-day moratorium on new coal and coal seam gas projects, a compulsory agriculture impact statement for new projects, and the exhibition of an aquifer interference regulation for public comment.

But none of these was required for Cockatoo's exploration licence, which stretches under Sutton Forest, and which its opponents say risks agriculture and valuable aquifers.

Mr Hazzard's office last night said he knew nothing about the approval of Cockatoo's exploration.

Southern Highlands Coal Action Group co-ordinator Tim Frost said his group, which has been waging a campaign against the mine at Sutton Forest, was surprised by the news.

"It's a matter of extreme regret that permission has been given to explore in the Belanglo State Forest without environmental impact statements being released," he said. "These things all seem to be done at the last minute in the dead of night.

"What we really need is complete transparency with these exploration licences."

Government minister and Member for Goulburn Pru Goward has supported the campaign against the mine, warning of its effect on aquifers. Ms Goward could not be reached for comment last night.

Hume Coal project manager Mike Cunnion said he was pleased the drilling could start.

"This program will be important in increasing our understanding of the coal structures within the Hume Project exploration lease," he said.

"It will also allow us to begin our extensive groundwater monitoring activities and demonstrate the high-levels of environmental standards which we hold ourselves to."

Hume Coal is a joint venture between majority owner Korean steel company POSCO and Australian miner Cockatoo Coal.

The exploration licence covers many multimillion-dollar properties at Sutton Forest.