Gas prices could fall by a quarter with shale drilling, Government advisers say In an optimistic scenario of high shale production in Britain and Europe, the price would fall 27 per cent, because of a "combination of local gas with falling production costs" and "readily available" imports. In only one "pessimistic" scenario, Navigant said gas prices would go up by 16 per cent over the next two decades. This would be caused by some sort of "political limitation" on the availability of imports or "US gas production declining before current expectations." "In two out of three of our scenarios we predict a fall in prices from current levels quite soon," the report said. Companies are currently in the very early stages of drilling for shale gas in Britain but local opposition could stop widespread exploration in the countryside. No-one yet knows how much - if any - can be recovered by fracking, the controversial process of blasting water, sand and chemicals into the ground to release the gas. However, estimates suggest northern England could provide enough shale gas to meet the UK's needs for more than four decades. This week, Mr Cameron gave some of his strongest ever comments in favour of shale gas. "In America they are now almost self-sufficient in gas," he said. Their gas prices to business are now less then half as much as ours are and the reason for this is they have put a lot of investment into unconventional gas. The figures are actually quite frightening. Europe as a whole has 75 per cent as much unconventional gas as America. So we've got less in Europe as America. But whereas they are digging 10,000 wells a year, so far in Europe we've dug just 100. So we are way behind, so I'm in favour of fracking, the government is making it easier. Following the new Navigant figures, a spokesman for the Department of Energy and Climate Change (DECC) said officials are relying on their own "robust" figures that predict gas prices will rise. "Forecasting gas prices far into the future is extremely challenging so DECC uses a number of independent reports to produce our assumptions," the spokesman said. Most analysts project global gas prices will remain firm in the longer term. This is because of the uncertainties of liquid natural gas availability and in predicting unconventional gas potential, combined with rising global gas demand.