Poland’s determination to continue providing financial assistance to coal power plants beyond 2030 has sunk an attempt to reform Europe’s electricity market, negotiators have said.

After an all-night session, European Union legislators failed to reach agreement on a proposed reform of the EU electricity market, part of a “clean energy package” of laws presented by the European Commission more than two years ago.

The session, which started at 18:30pm on Wednesday (5 December) ended at 06:30 in the morning after without a deal.

“After 12 hours of negotiation, the Council still defends coal subsidies until 2035. This is simply unacceptable,” said Florent Marcellesi, a Green lawmaker from Spain who was part of the European Parliament delegation at the talks, according to Euractiv.com.

A new “trialogue” meeting has been scheduled on 18 December to try and find an agreement between the EU’s three law-making bodies – the Parliament and the Council of Ministers, under the watch of the European Commission acting as an arbiter.

The collapse of the EU talks is a warning shot for world nations meeting at the UN climate summit in Katowice, Poland.

Poland is advocating a “just transition” at the UN meeting, which is expected to adopt a rulebook to implement the Paris Agreement goal of keeping global warming “well below 2°C”.

But the EU’s failure to move forward on the power market reform illustrates the difficulties of managing the country’s transition away from coal. Poland is dependent on coal for nearly 80% of its electricity needs.