The Government has proposed new rules to simplify the granting of access for fracking as a study of the Weald Basin, which stretches from Wiltshire to Kent, could be harbouring up to 8.5 billion barrels of shale oil.

Under the proposals underground access for shale oil and gas developments allowed under 300 metres.

Those living above ground would receive a voluntary payment of £20,000 per well.

A report by the British Geological Survey (BGS) has found there are an estimated 4.4 billion barrels of shale oil in vast parts of southern England while a study of the Weald Basin found there could be 2.2-8.5 billion barrels of shale oil there.

The BGS stressed that these numbers are for resources and not reserves. Shale oil exploration in the US has only been able to access up to 10 per cent of the total oil.

By comparison to the Weald Basin figures, around 40 billion barrels of oil have already been extracted from the North Sea, and the study found there was unlikely to be any shale gas potential in the area.

And any hopes of an oil bonanza in southern England must be tempered by the possibility that the reserves could be difficult to extract.

Professor Andrew Aplin, from Durham University, has identified three problems which he thought could affect the exploitation of reserves identified in the Weald area spanning Sussex, Hampshire, Kent and Surrey.

The professor of unconventional petroleum from the department of earth sciences, said: "The interesting question is how much of the oil that has been identified might be recoverable.

"A careful look at the data in the report suggests that much of the oil in the shales is tightly bound to the rock and therefore difficult or impossible to produce.

"If there is any free - and therefore potentially producible - oil in the shales, there are two further problems.

"Much of the shale sequence in the Weald is clay-rich, which US experience suggests is difficult to fracture effectively.

"Also, the chemistry of the oil in much of the area is likely to be quite heavy and thus will not flow easily; in contrast, the shale oil which is being currently produced from areas such as the Eagle Ford in the USA is much lighter and thus flows more easily.

"This relates to the temperature to which the shales have been buried in the geological past."

Prof Aplin, responding to a report by the British Geological Survey which suggested there may be five billion barrels of oil in the Weald shales, said US experience showed at best only five per cent could be extracted from shale.

He added: "Since neither the rock nor the oil is of optimal quality in the Weald, we might estimate that one per cent of the Weald oil resource might be recoverable.

"This would equate to 0.05 billion barrels, which is about two months' UK consumption.

"From a national perspective, this seems to be a rather small prize."

Robert Gatliff, director of energy and marine geoscience at the BGS, said: "It's not a huge bonanza. But we have to see what happens and we won't really know the answers until we have got some more drilling and testing."

When asked if the findings were a let-down for the Government, Energy Minister Michael Fallon replied: "It's not a let-down or a let-up. It is what it is.

"It's a potentially home-grown source of energy that we simply cannot afford to ignore. That is why we're encouraging this development through streamlining and simplifying the regulatory process while protecting the environment."

He went on: "We are keen for shale and geothermal exploration to go ahead while protecting residents through the robust regulation that is in place.

"These proposals allow shale and geothermal development while offering a fair deal for communities in return for underground access at depths so deep they will have no negative impact on landowners."

When asked why the Government was promoting the use of a fossil fuel, Mr Fallon said: "There's nothing particularly green about tankering oil all the way across the world from the coast of Africa or from Russia if we have it here."

The minister insisted that shale gas, oil and geothermal operations would be carried out at depths so deep they will have "no negative impact on land owners or home owners".

But Greenpeace UK energy campaigner Lawrence Carter said: "Stripping away people's property rights while trying to kick off a Klondike-style shale oil rush in the Home Counties is a highly toxic policy mix.

"The Tories have just taken a bruising at the local elections - fracking will only make things worse for Tory MPs in the party's heartlands at next year's vote."

He added: "Dangling larger bribes in front of communities won't quell their deep concerns about fracking. People know very well you can't put a price on clean air and water, unspoilt countryside, and a stable climate.

"Falling support for fracking shows the bungs and bulldozers approach isn't working. Ministers should look at more practical solutions to boost our energy security, like slashing waste and promoting clean renewable energy sources."

Ministers firmly back the exploitation of shale gas reserves in rocks beneath the UK, claiming it could bring down energy bills and create thousands of jobs.

Environmental activists are bitterly opposed to the technique, which opponents say can increase climate change, cause small earthquakes and pollute water supplies.

Prime Minister David Cameron has insisted that fracking will be "good for our country" and has blamed a "lack of understanding" of the process for some of the opposition.

The consultation launched today will be open for 12 weeks and the Government will announce further steps once feedback has been considered.