The participants will unite for a "world powered by 100% clean and safe energy, where quality jobs benefit the people and the planet", NGO Umanotera, one of the organisers, has said.

The rally, starting at 11 AM, will be addressed by Mayor Zoran Janković, explorer and photographer Matevž Lenarčič, Ljubljana Auxiliary Bishop Franc Šuštar and the heads of Greenpeace Slovenia and Umanotera, Nina Štros and Gaja Brecelj, among many others.

The rally, as part of which workshops for children will also be held, was set up by Umanotera, cultural and environmental society Smetumet and Greenpeace Slovenija.

NGOs from all over the world planned to hold two big rallies in Paris ahead of the conference but were forced to cancel them in the aftermath of the terrorist attacks in the French capital.

Instead, rallies will now be held in cities from Melbourne to Tokio and from Manila to Los Angeles. "29 November will therefore be the day of the biggest campaign in the history of our battle against dirty energy that poisons our communities," the organisers said.