If successful, the council will almost certainly mount a legal challenge against AGL's application for a power station 15km south of Campbelltown's CBD at Leafs Gully, along Appin Road.

Planning Minister Kristina Keneally's approved development of the $200 million power plant in August.

The plant will operate about 15 per cent of the year but Ms Keneally indicated its operations could be expanded in the future. The council has engaged the services of law firm DLA Phillips Fox to search for flaws in the State Government's approval process.

The council wants to know what its chances of success in court are prior to proceeding with a costly appeal process.

Campbelltown Mayor Aaron Rule said it was appropriate that council spend money to fight the power-plant approval.

``This has been a major issue,'' he said. ``The fight against the power plant is a fight to protect the future of the Campbelltown community.''