Conservation groups have welcomed a ruling by the Law Lords which they say will help to protect thousands of sites important for their wildlife and landscape features.

The ruling says permission granted up to half a century ago for quarrying must now be subjected to an assessment of the environmental impact.

The case concerns the Wensleydale village of Preston-under-Scar, in North Yorkshire. A local landowner was given permission 50 years ago to quarry near the village.

No quarrying has in fact taken place. But the local mineral authority, North Yorkshire County Council, reviewed the permission four years ago, and said quarrying could take place there until 2046.

Two neighbours from the village challenged the decision, which they said threatened rare limestone grassland and ancient woodland. The quarry site is home to many rare plants, including mountain pansy, rock rose and salad burnet.

The Court of Appeal upheld their claim that the county council should have demanded an environmental impact assessment, which is required under both European Union and British law.

Widespread effects

And now the Law Lords have unanimously endorsed the Court of Appeal ruling, in a decision likely to have profound implications.

The villagers' case was supported by the World Wide Fund for Nature and the Wildlife Trusts, the national body which co-ordinates the work of 46 county trusts.

The trust's Director-General, Dr Simon Lyster, welcomed the Law Lords' "milestone" ruling.

New hope for the few remaining peat bogs

"This is truly a landmark victory for wildlife. The environmental effects of quarrying, peat extraction and other mineral extraction on thousands of other sites will now have to be rigorously assessed.

"This is especially important for our vulnerable peatlands. Currently all but 6% of peat bogs have been destroyed by factors including extraction."

A spokesman for the North Yorkshire branch of the Council for the Protection of Rural England, which also supported the case, said he hoped the result would have "an enormous impact".

"These consents from years ago have been hanging over much of the north of England like a sword of Damocles."

The consents were originally given, with no planning conditions attached, to ensure there would be enough raw material to rebuild Britain after the second world war.

Similar consents continued to be granted until the 1980s, and thousands are thought now to be due for review.

All will be affected by the Law Lords' decision.