An eventful plenary session at the UN climate summit has ended with the surprising announcement that Connie Hedegaard has stepped down from the COP presidency and been replaced by Danish Prime Minister Lars L?kke Rasmussen.

Danish Minister for Climate and Energy Connie Hedegaard (L) meets with former U.S. President Bill Clinton at the Clinton Global Initiative in New York September 21, 2009.? [Xinhua/Reuters File Photo]

"With so many heads of state and governments arriving to give their statements, it is appropriate that the Danish prime minister presides. Negotiations and consultations will be conducted at all levels. Who would have believed that in Bali two years ago?" Hedegaard said. Thus, the official line is that the move is procedural and planned. But it hadn't been signalled earlier and has led to speculation of friction between Hedegaard and L?kke Rasmussen.

The prime minister has appointed Hedegaard as his special envoy in informal negotiations and consultations.

L?kke Rasmussen said the 115 heads of state and government taking part in the conference indicated there was a strong desire for a successful outcome in Copenhagen.

"This historical will to address the climate challenge is the strongest possible driver for a global agreement," he said.

"The final negotiations will be tense and strenuous. I have therefore asked Connie Hedegaard to continue to negotiate the Copenhagen outcome with her colleagues," L?kke Rasmussen said.