Ms Darling, speaking on ABC Radio on Wednesday, said recycling, mining on Stradbroke Island and coal-seam gas were the key environmental issues in the lead up to the March 24 election.

Ms Darling said she believed it was impossible to fully restore and rehabilitate some island ecosystems on the island after mining and said the best that could be done was "revegetation".

"That's why legislation to restrict sand mining and ultimately end the sand mining on the island is very important," Ms Darling said.

"So not only has the government put timelines to stop sandmining we also made sure those sensitive areas are not touched at all.

"It's always best not to disturb the environment," Ms Darling said.

Ms Darling also said the success of revegetation would not be known for another 30 years.

Under the State government's Stradbroke Island Sustainability and Protection Act heavy mineral mining will continue on the island until 2019 and 80 per cent of the island will be national park by 2026.

The opposition LNP has said if elected, it would "turn back the clocks" to allow mining giant Sibelco to continue on now-extinct mining leases.

Cleveland MP Mark Robinson, whose electorate covers the island, said the government's 2019 deadline for the end of mining was not long enough.

"The LNP has never said sandmining would continue forever," Mr Robinson said.

"Under an LNP government, we would go back to original agreements and timeframes, which were set between the government, the mine and the community," he said.

Mr Robinson said Ms Darling was "hypocritical" for questioning Sibelco's revegetation program, which won a 2008 environment award from the government.

"The mine is also operating under strict regulations introduced by this government," Mr Robinson said.

Island environmental group Friends of Stradbroke Island said the government policy to allow mining to continue for another 14 years was "irresponsible".

Group spokesman Nikki Parker called for the immediate end to mining on the island and said Ms Darling knew the damage from sand mining was irreversible and threatened endangered species.

"This policy is continuing to degrade tourism nature conservation values and threatening the internationally significant 18 Mile Swamp wetland with pollution," Ms Parker said.

"Areas subjected to open-cut sandmining can only ever be 'revegetated' but the original ecosystems can never be rehabilitated," Ms Parker said.