U.N. talks over a global climate treaty might be slow and tedious, but the European Union is putting its "green" credibility on the line as opposition from some member states threatens to derail the EU's energy and climate package.

EU ministers are meeting in Brussels Thursday and Friday for a crunch summit that aims to resolve disagreements over the body's climate and energy package.

The EU has pledged to cut greenhouse gases by 20 percent, boost the share of renewables in the energy mix to 20 percent and reduce energy consumption by 20 percent -- all by 2020.

Yet the financial crisis has jeopardized the so-called 20-20-20 plan, with some member states -- mainly Poland, Germany and Italy -- arguing the agreed emissions cuts are too ambitious and too costly.

French President Nicolas Sarkozy, the holder of the EU presidency, over the weekend at a meeting in the Polish city of Gdansk tried to bring these countries back on board, arguing the bloc's credibility on climate protection was on the line. Yet on Wednesday it was still unclear how much opposition Paris would face in Brussels.

The EU summit is especially crucial as it coincides with a U.N. meeting in the Polish city of Poznan, where nearly 189 countries are setting the path for what observers hope by late 2009 will become the most ambitious climate deal the world has ever seen.

"The EU leadership on climate change has been extremely important to keep momentum going forward," Elliot Diringer, an expert with the Pew Center on Global Climate Change, said Wednesday.

Yet not everyone expects the EU to continue to lead.

A coalition of environmental groups in an open letter to Sarkozy earlier this week blasted the actions of some member states.

"At a time when we need Europe to lead, too many EU countries are failing in their responsibilities to address the threat of climate change," the letter said. "Inexcusably, several countries are trying to get out of their own climate commitments by pushing for two-thirds of their reduction in greenhouse gas emissions to be met by purchasing offset credits from outside the EU."

Poland, which produces nearly 95 percent of its electricity from dirty coal, has said it needs more money and time to turn around its power plants park. Warsaw therefore has lobbied for lower emissions cuts and a delay of the Emissions Trading Scheme, which requires the EU's big power stations to buy emissions permits.

Italy and especially Germany, Europe's largest economy and once a leader on climate protection, are concerned that their energy-heavy industries will suffer if they have to enlist in the ETS.

German Chancellor Angela Merkel instead wants German companies to be able to buy permits that would allow them to pollute. "Iron Angie" has resisted Sarkozy's French charm on several issues, vowing to a German daily newspaper that she won't agree to an EU package that would "endanger German jobs."

Last week Merkel denied Sarkozy's call for more German money to support an EU-wide economic stimulus package. Then she frustrated EU leaders until they agreed to softer emissions cuts for the car sector -- a key German industry.

Observers say Germany needs to play for the team if the EU wants a successful conclusion of the summit.

"Without Germany it will not be possible this week to reach a reasonable agreement in Brussels," Luxembourg Prime Minister Jean-Claude Juncker told German radio earlier this week.

Yet European politicians on Wednesday in Poznan said this week's EU summit would see a successful ending.

Guido Sacconi, one of the members of the European Parliament behind the EU's car emissions legislation, said member states were nearing an agreement on the ETS.

And Stavros Dimas, the EU's environment commissioner, vowed to reporters that the EU would keep its leadership position when it comes to climate protection.

No matter the detailed look of the package, he said, "the reductions targets … and the other targets that we have set for renewables -- so the environmental integrity of our package -- will remain intact."