Britain' biggest private sector union has warned of potential blackouts this winter if action is not taken to address a shortage in power generation.

The Amicus union said on Monday that a combination of cold weather, EU directives and the closure of nuclear stations could cause a crisis in the country's electricity supply.

Brussels has ordered that carbon emissions must be shut, while a cold snap could lead to higher demand for domestic fuel.

Meanwhile the closure of magnox nuclear power stations could compound the problem if action is not taken, Amicus officials claimed.

General secretary Derek Simpson said the government must invest in new clean coal fired generators or face the "real possibility" of blackouts.

"Dire consequences could follow if the action Amicus is demanding is not taken," he said.

"We could be suffering routine blackouts in the next few years and the sort of energy price hikes we have seen in recent weeks because of the increasing reliance on foreign supplies from unstable countries.

"The impact of new European legislation must be thoroughly investigated. The government needs to act to encourage coal fire generating plant owners to equip their power stations to reduce carbon emissions, and comply with new EU directives.

"A programme of publicly funded research and development for clean coal technology must be undertaken as part of a long term energy policy for the UK. This has to be backed up by investment in the UK's power engineering and manufacturing sector to develop expertise in the design and construction of new power stations."

However energy regulator Ofgem said more power will be available this year than 12 months ago, while a Department of Trade and Industry spokesman accused the union of "scaremongering".