A third of Europe's most climate polluting power stations are in the UK, a new report from the WWF has found.

The report, titled Dirty Thirty, reveals that 10 of Europe's 30 biggest emitters of carbon dioxide are located in Britain.

And according to the WWF report, the combined emissions from these 10 power stations surged by nearly five per cent in 2006.

The biggest polluter in the UK was Drax station - which is twice the size of any other UK station - and released some 23 million tonnes in 2006, up 10 per cent on the previous year, the WWF said.

The other biggest polluters were Scottish Power's Longannet station and EDF Energy's Cottam station, which each emitted over 10 million tonnes of CO2.

Emissions from Longannet and Cottam increased by more than 20 per cent between 2005 and 2006, the study warned.

In March, a WWF report showed that the total emissions from the UK power sector have risen by 28 per cent since 1999.

Dr Keith Allott, head of climate change at WWF-UK, said: "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.

"The dash for gas in the nineties helped drive down carbon emissions almost by accident - but the power sector is now on a 'roll to coal' with profound environmental implications.

"If the government wants to maintain international credibility on climate change, it must dramatically increase and diversify renewable energy, curb energy demand and provide the power sector with incentives or legislation to reduce coal burn."

In 2006, the top 30 polluting power stations were responsible for around 393 million tonnes of CO2, some 10 per cent of all EU CO2 emissions.

The WWF believes that it is essential to have a stronger EU Emissions Trading Scheme that delivers significant emissions reductions by encouraging investment in cleaner and more efficient plants.

Europe's dirtiest power stations are all coal-fired. The least efficient stations, in Greece and Germany, run on particularly CO2-intense lignite.

The UK stations on the list run on hard coal, and are relatively efficient compared to these, the WWF noted.

Most of the "Dirty Thirty" are located in Germany and the UK (10 plants each), followed by Poland (4 plants).

Just four companies account for most of Europe's dirtiest power stations. More than half of the 30 plants analysed are run by RWE (Germany), Vattenfall (Sweden), EDF (France) and EON (Germany).

RWE and Vattenfall are also the EU's largest corporate climate polluters.