NSW Opposition Leader John Robertson brought his anti-coal seam gas message to the Illawarra yesterday as Liberal Party MPs who say he helped authorise new mines while in power accused him of hypocrisy.

Mr Robertson wants the State Government to suspend all coal seam gas exploration licences in the Illawarra until the long-term effects are fully understood.

It’s a message Mr Robertson has been taking around the state as opposition grows to the mining practice which involves releasing trapped gas.

Environmentalists and farmers say coal seam gas mining could pollute underground aquifers and potentially drinking water.

Mr Robertson said better understanding of coal seam gas risks was needed.

‘‘I’m calling on the O’Farrell government to act now to protect areas like Darkes Forest here in the Illawarra from coal seam gas mining,’’ he said.

‘‘The impacts of coal seam gas mining on aquifers and groundwater, hundreds of metres below the surface, are not yet fully understood.’’

Member for Keira Ryan Park said while the gas industry had the potential to deliver significant economic benefits, further drilling shouldn’t be allowed ‘‘at the expense of local communities and our precious water resources’’.

‘‘It is absolutely staggering when you look at maps of the Illawarra, overlaid with existing coal seam gas exploration licences ... the entire region is exposed and the water table underneath it,’’ he said.

However, Mr Robertson’s stance drew criticism from the Liberal Party.

Kiama MP Gareth Ward said coal seam gas licences were approved and extended while Labor was in power.

‘‘Given the fact that Mr Robertson oversaw the issuing of licences while in government, for him to now oppose coal seam gas in opposition is the height of hypocrisy,’’ Mr Ward said.