BRUSSELS: The European Union's executive outlined plans on Wednesday to tax high-energy fuels, a move users fear could push up the price of diesel but which EU officials hope will help fight global warming.

The blueprint, which could become EU law by 2013, attempts to make tax on motor fuels, in particular, more environmentally friendly, by raising the minimum levy on polluting diesel to bring it into line with petrol.

But the framework, which carmakers and motorists worry could inflate the price of diesel because its high-energy content puts it in line for steeper taxes, has put Brussels on a collision course with Europe's biggest car producer, Germany.

Under the plans, Germany's tax on diesel would have to rise from 47 cents per litre to 75 cents in 2020, undermining Berlin's subvention for the fuel that supports carmakers such as BMW and Daimler.

Chancellor Angela Merkel has already said she opposes the Brussels initiative, even though it would be phased in over a decade.

"Our common goal is a more resource-efficient, greener and more competitive EU economy," said Algirdas Semeta, the European commissioner in charge of taxation. "This proposal sets a strong CO2 price signal for businesses and consumers."

Over the next decade, the European Union plans to cut by a fifth its emissions of carbon dioxide, the gas most blamed for climate change.

But the current system of taxing energy use across Europe undermines that ambition, because it puts the lowest levies on the biggest polluter, coal, and imposes the highest burden on one of the least carbon-intensive, bioethanol.

European countries also vary in their approach to taxing energy.

Semeta plans to change all that with a new fuel tax that includes a levy on carbon emissions and a minimum tax on motor and heating fuels. Under the scheme, tax on coal would rise.

The planned overhaul of Europe's 240 billion euro ($347 billion) annual taxation of energy would also make green fuels cheaper.

Fuels made from plant biomass -- such as wood pellets, bioethanol or biodiesel -- would have less tax, because in some cases they can absorb almost as much carbon when they are grown as is released when they are burned.

The scheme would extend environmental controls beyond industry to households and consumers. Big companies already have to pay for polluting, by buying permits for carbon emissions which can be traded on the EU's Emissions Trading Scheme.

Carbon taxation is used by Denmark, Sweden and Ireland, while Britain, Germany and the Netherlands have various eco-taxes.

Semeta's attempt to overhaul fuel taxes last summer stalled over concerns about the impact on business. He also faces long-standing resistance from countries to interference from Brussels on tax.