The impact of development on Britain's wildlife must be better offset by the creation of new country parks and other large-scale projects, Tory leader David Cameron said today.

He said the Opposition was considering the introduction of "conservation credits" that could be pooled by communities to create large-scale projects rather than token efforts to 'green' individual new buildings.

Speaking as he toured Chimney Meadows Nature Reserve in Bampton, Oxfordshire, he said parts of Britain's natural heritage could "so easily be destroyed in the name of progress".

"At the moment we have a pretty unimaginative system where every new development has to tick boxes in terms of protecting habitats and wildlife.

"Yes, some of those boxes must be ticked, but there are no real incentives for conservation. It's time to be more imaginative.

"Instead of regulation alone, it would be better to give communities and businesses the incentives to do the right thing and pool the resources from development to create larger conservation projects that can benefit everybody."

Likening it to the accepted systems of "credits" for carbon emissions, he said: "The idea, to put it simply, is that any cost to biodiversity, through something like development, is compensated for by at least an equivalent investment in biodiversity elsewhere.

"So instead of simply planting trees on a small patch of land on the edge of a new housing development, for example, conservation credits would allow several developments in one area to be pooled to create large habitat projects.

"This could be a new country park or community woodland, so there was somewhere for local children to play and learn about their environment.

"It could be new wetlands, or a new wildlife reserve. These projects would not only provide significant enjoyment to people, they would also create new habitats in which nature can survive and thrive.

"Conservation credits are about placing a value on biodiversity for the first time, because only if you place a value on something can you truly compensate for loss."

It was important to ensure any new system did not thwart plans for more affordable homes, create more red tape or get in the way of responsible businesses' existing environmental efforts, he warned.

Shadow environment secretary Nick Herbert would set up a "review into the scope for introducing a system of conservation credits in England", to examine such issues, he said.