Britain's gas supplies are threatened by shortages in the next decade, as electricity companies build more gas-fired power stations and domestic gas production declines, according to a report commissioned by the industry.
As a result, gas prices are likely to rise well above today's levels. The warning comes as Eon UK, one of the country's biggest energy suppliers, cautions that it has reached "five minutes to midnight" in the effort to provide the electricity Britain will need in the 2010s.
In the energy white paper last month, Alistair Darling, the trade and industry secretary, set out plans to cut reliance on gas imports in 2020 from 80 per cent of its needs to 60 per cent.
But industry experts are sceptical that that ambitious goal can be achieved.
The report, from the consultancy Pöyry and commissioned by Oil and Gas UK, the trade association, argues that for the next seven years or so, Britain will have "capacity excess" for gas. With pipelines from Norway, the Netherlands and Belgium being opened and expanded, and new terminals to import liquefied natural gas under construction, Britain's potential gas supply could, by next year, be more than 50 per cent greater than demand.
From then on, however, the balance will swing back again. After about 2014-15, Britain may find it has less gas than it needs.
The demand for gas largely depends on how many new gas-fired power stations are built. Between a third and a half of Britain's electricity generation capacity is due to go out of service over the next 15 years or so, as old nuclear plants reach the end of their lives, and old coal-fired plants become uneconomic under new European Union regulations.
In the words of Vincent de Rivaz, chief executive of EDF Energy, another of the big energy suppliers, it looks as though there is a "power crunch" coming.
The government's answers are renewables, new nuclear power, and perhaps "clean coal" power stations that capture their carbon dioxide emissions.
But many in the industry think the most likely outcome will be a new "dash for gas", repeating the rush to build gas-fired power stations that began at the end of the 1980s. Gas-fired power stations are much cheaper and quicker to build than the alternatives.
Clean coal, meanwhile, is a technology that is not in commercial use, and the competition for a government package to support a prototype plant will not even be launched until November.
That is the fear behind a speech to be given today by Paul Golby, the chief executive of Eon UK. Addressing Prospect, the technical union, he will argue that the government urgently needs to put in place the policies to encourage nuclear power, clean coal and more renewable energy, or it will leave the second "dash for gas" as the only way to keep the lights on.
Growing reliance on gas also has worrying implications for Britain's security of supply, at a time when the Pöyry report forecasts that the output of Britain's gas fields will fall from about 70bn cubic metres this year to just 20bn in 2016.
Forecasts of energy supplies and demand are subject to uncertainty, depending on inherently volatile factors such as the weather. In 2000, the industry expected that domestic production would supply all the gas Britain needed in 2005. In the event, more than 15 per cent had to be imported.
But Pöyry suggests the pressure is on the government to accelerate alternatives to gas-fired power generation, and to make sure Britain can extract as much gas as possible from its dwindling reserves. Perhaps more than either, it needs to curb the demand for electricity, because only then could the white paper's promise of cutting dependency on imported gas be delivered.
