The NSW government should halt coal seam gas (CSG) mining in western Sydney, where there is growing anxiety among residents, Greens MP Jeremy Buckingham says.

Mr Buckingham says a Greens doorknocking campaign to educate western Sydney residents about CSG has found they are already aware of the industry, and they don't want it in the area.

"They understand it's bad. They don't want it and they want their politicians to act," he told AAP.

Energy company AGL last week suspended its proposed expansion of a CSG project in Camden due to community concerns.

The Greens said AGL's suspension was merely a delaying tactic because the company knew it wouldn't get approval.

Mr Buckingham has criticised Premier Barry O'Farrell for not knocking back the expansion, saying the community wants the exploration licence cancelled across Sydney.

He says the issue will be a principal focus for the Greens in the lead up to the federal election.

"We will raise the issue in state and federal parliaments, demanding that Labor and the coalition put their position on the record, if they're for CSG or against it."