EU environment ministers started a key meeting Thursday as wrangling over pollution trading rights held up a major climate change accord that the EU wants passed at a summit next week. Germany, Europe's biggest economy, and Poland are leading opposition to the scheme under which rights to pollute would have to be bought. "We are going to defend our positions," Chancellor Angela Merkel told the German parliament in Berlin. The trading scheme was just one of the problems identified by French Environment Minister Jean-Louis Borloo in a speech to the European Parliament before chairing the Brussels talks. Poland and other eastern European nations also want special dispensations in the carbon dioxide (CO2) emissions rules because of their dependence on coal for power. The German and Polish environment ministers did not attend Thursday's talks, leaving lesser officials to take their place. EU nations last year agreed a broad plan to cuts CO2 levels by 20 percent in 2020 compared to 1990, 20 percent cuts in energy use through efficiency measures and 20 percent of energy needs coming from wind, water, solar and other renewable sources, again by 2020. Each nation has sought to protect its own industries and economies in talks however. Italian Prime Minister Silvio Berlusconi may also prove difficult to persuade, fearing industry could move elsewhere where such costs and restrictions do not apply. Some ministers have expressed cautious optimism however. "I have found the French compromise is a good one so hopefully this will be accepted by all member states by the end of this year," said Czech Environment Minister Martin Burlik, whose country will assume the EU presidency in January. "I'm hoping that our negotiations will be successful. I'm very optimistic," said Austrian counterpart Nikolas Berlakovich. "The negotiations are entering a crucial phase, and while 90 percent of the text has been finalised, there are still many difficult questions under discussion," said Borloo. "The most difficult is the mechanism for auctioning carbon emissions." France hopes to reach agreement on the climate change package before it hands over the EU presidency to the Czechs. The EU wants to enter international talks on climate change in Copenhangen next December with a unified position. And some nations fear that too much diluting of the European package will undermine its main objectives at the global talks. Germany wants most emissions allowances to be free for industry, whereas the EU proposals would have the percentage auctioned off gradually increased up to 100 percent in 2020, when every tonne of CO2 will have to be bought. Poland has rejected one French compromise to give at least half of the polluting permits free until 2016 and at least 60 percent for electricity produced from coal-fired plants. However offers in a new draft proposal, including ways to keep carbon costs when energy costs rise, appeared to be helping win Warsaw over. Poland's Prime Minister Donald Tusk said Wednesday an agreement was "close". "I think that we are close to a version acceptable for Poland... a version that will allow us to avoid a veto," he told reporters. Tusk and other eastern European leaders will met in Gdansk, Poland with French President Nicolas Sarkozy on Saturday for climate talks. Sarkozy hopes to seal the deal at a full EU summit in Brussels next Thursday and Friday, before France hands over the EU presidency.