Researchers from the British Geological Survey have identified shale gas reserves stretching across the north of England. These reserves, far larger than previously documented, lie under cities such as Manchester, York and Leeds.

The discovery comes as the government announced fast-track measures and tax breaks for shale gas exploration.

This process involves fracking, or pumping water and chemicals underground in order to force out the shale gas.

Last week, a surveyor warned a lack of clarity on where fracking will take place could cause house prices in affected areas to fall by as much as 30%.

Valunation managing director Alison Beech said while it was difficult to measure the actual impact of fracking there were worries about tremors and possible water pollution.

She said: “Despite the wide publicity and protests, it is just too early to gauge any adverse effects on house prices or demand, but it is obviously vital for surveyors in affected areas to be alert to any market reaction.

“For the time being, it is important not to over react but surveyor reports should offer an appropriate comment in localities where this could assume greater importance. There does not yet seem to be any information regarding the geographical extent of possible physical effects.”

Even in the absence of physical damage, public worries about fracking could have a knock-on effect on mortgage valuations, she added.

On the other hand, the increased economic activity could have a positive impact on the local housing market.