GIANT salt caverns are to be carved out under the sea off the North-East and North Yorkshire coast so they can be used to store gas, it has been revealed.

The move is part of measures to stave off gas shortages and price rises in the future.

The caverns are manufactured by pumping water under the sea bed to dissolve naturally-occurring salt deposits. They can be hundreds of metres wide, deep and underground.

Yesterday, the Department for Trade and Industry, which unveiled the plans, would not reveal the exact location of the cavities for commercial reasons.

Experts from the British Geological Survey (BGS) have selected two areas, a portion of the southern North Sea, off the North-East coast and down to Lincolnshire, and a chunk of the Irish Sea, off Blackpool.

Storing pressurised natural gas in the giant caves would enable it to be retrieved rapidly to cope with demand. The measures would also allow tankers to unload offshore.

Trade Secretary Alan Johnson said: "North Sea gas reserves are declining quicker than expected, we are importing more gas, and gas supply technology is developing rapidly. We need to plan ahead today so we will be able to meet our energy needs tomorrow.

"The measures I propose will put the UK at the forefront of gas storage technology and secure increased gas supplies for the UK."

Nick Riley, of the BGS, said there was a minor risk with underground storage.

"There have been incidents of gas escaping and fires starting, but it is extremely rare. It is never the geology that fails, it is the engineering," he said.

"After the explosion at Buncefield oil depot, at Hemel Hempstead, we need to consider underground storage. We were very lucky that was on a Sunday."

The caverns are dissolved away in a controlled way, using foam to make sure they are spherical.

Mr Riley said there was also potential to store energy generated by off-shore wind farms in salt caverns.

There is already a vast underground storage facility in this region. Hydrogen has been stored under Teesside for many years.