The London Olympics in 2012 are likely to be hit by electricity blackouts, according to a poll of energy experts.
Could the lights be going out on the London Olympics?
Three-quarters of the respondents to a survey organised by the energy company Mitsui Babcock identified blackouts as a "serious concern".
Many of the UK's nuclear and coal-fired stations will have closed by 2012, and demand for electricity is rising.
A majority of the respondents also said the UK would not meet its Kyoto treaty target on greenhouse gas emissions.
The survey polled 140 experts from industry, government, academia and environmental groups on their attitudes towards energy issues.
Mitsui Babcock is one of several companies in the fossil fuel, renewables and nuclear business which have urged the government to stimulate investment in new generating plants by establishing a long-term regulatory framework.
"There is a growing gap in our energy needs," said Iain Miller, Mitsui Babcock's chief operating officer.
"According to economists, finding an urgent solution will require billions of pounds of investment. We will see energy blackouts unless we act immediately."
All 140 respondents to the survey said that the best way to ensure energy security for the future lay in a diversified mix of electricity generation, including renewables, coal, gas and nuclear.
Sir Digby Jones, director general of the CBI, said: "We cannot allow such levels of uncertainty to persist in a major industrial power like the UK.
"We face some major decisions over our approach to energy in this country. If these decisions are got wrong, or simply put off, the business need for secure energy supplies at internationally competitive prices will become ever harder to meet."
The survey asked questions on progress towards meeting Britain's Kyoto Protocol target of reducing greenhouse gas emissions 12.5% below 1990 levels in the period 2008-2012.
Currently, emissions are slightly below that target, but have risen in the last few years, partly as high gas prices bring a switch to coal for generating electricity.
Three-quarters of the poll respondents believe Britain will miss its target, with reasons given including insufficient policy mechanisms, lack of investment in clean technologies, and lack of voter support for tough decisions.
Eighty-eight percent placed responsibility for reducing emissions with the government.
Nuclear power supplies about 20% of the nation's electricity; but by 2012, nine of the 12 stations still operating will have closed.
A significant number of the existing coal-fired stations may have closed too under the European Union's Large Combustion Plants Directive.
A recent report from a wide-ranging academic group said these closures, combined with rising demand, could lead to a 20% shortfall in supply by 2015.
The 2003 Energy White Paper rules out new nuclear stations on economic grounds, though the government recently launched a review which could reverse that policy.
The White Paper sees gas as the dominant fuel; much of that gas would have to be imported as UK resources dwindle, and the government believes a liberalised international market is the best way to ensure an affordable supply.