The EU has criticised the glacial pace of UN negotiations on a global deal to combat climate change due to be signed in Paris this year, in a sign of the growing unease among some countries about the eventual outcome of the agreement.

“Time is of the essence here,” said Ilze Pruse, a senior EU delegate, as a week of talks ended in Geneva where representatives from more than 190 nations produced an official negotiating text for the Paris pact, due to be signed in December.

The draft document ballooned from fewer than 40 pages to 86 pages during the week and is full of what Ms Pruse said were repetitive options that could have been easily trimmed before envoys knuckle down to the far harder task of deciding what may actually stay in the agreement at their next scheduled negotiating session in Bonn in June.