UK power stations are reportedly contributing an increased amount to the EU's total emission levels.
A new study says that ten of Europe's 30 'dirtiest' power stations are based in Britain, with total emissions from the plants rising eight per cent in the last year.
WWF, which compiled today's report, says there is a "real danger" of the UK returning to a reliance on coal, with previous research suggesting that total emissions from Britain's power sector have increased by almost a third since 1992.
Drax Power Station, by far the largest in Britain, is named as the least efficient plant in the UK by WFF, with the facility said to have emitted 23 million tonnes in 2006 alone.
Other power stations on WWF's list include Scottish Power's Longannet station and EDF Energy's plant at Cottam.
"The UK's welcome attempts to show international leadership on climate change are being undermined by the dismal failure to cut our own emissions or to reverse our increasing reliance on coal, the most polluting energy source of all," said WWF-UK's head of climate challenge Dr Keith Allott.
"The dash for gas in the 90s helped drive down carbon emissions almost by accident but the power sector is now on a 'roll to coal' with profound environmental implications."
Although ten per cent of all carbon emissions in the EU come from British stations, WWF notes that the least efficient facilities on the continent are in Greece and Germany.
The Department of Trade and Industry says that in order to ensure Britain has the energy supplies it needs it is important to have a "diverse mix", claiming that coal accounts for a third of the country's electricity supply.
"While many of the UK's coal stations are due to close over the next five to ten years, it remains an important part of our energy mix as we develop lower carbon forms of power including renewables and cleaner ways of using fossil fuels," a spokesperson said.
"The government is investing heavily in low carbon energy and the establishment of a price for carbon through emissions trading providing an incentive for industry to move away from polluting forms of energy."
Commenting on WWF's research, the Liberal Democrats' environment spokesman Chris Huhne said that the government needed to provide incentives to "clean up coal and retire the worst plants".
"UK electricity generators are going back from gas to the use of the worst climate-destroying coal sources," he said.
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