Carrying blood-red ribbons to represent the crucial red lines already crossed by Cop26 negotiations, hundreds of representatives of global civil society walked out of the convention centre in Glasgow on the final morning of the summit in protest.

The audience at the People’s Plenary in the conference blue zone heard speakers condemn the legitimacy and ambition of the 12-day summit before walking out to join protesters gathered on the streets beyond the security fencing.

“Cop26 is a performance,” the Indigenous activist Ta’Kaiya Blaney of the Tla A’min Nation told the meeting before the walkout. “It is an illusion constructed to save the capitalist economy rooted in resource extraction and colonialism. I didn’t come here to fix the agenda – I came here to disrupt it.”

Tracy Bach of the advocacy steering group Ringo, shot down claims that this summit was “the most inclusive Cop ever”, telling the audience: “Most of the observers sitting here right now have not had access to the negotiation space.”

Singing and whooping, representatives of farmers, Indigenous people, youth, women, academics, trade unions and environmental NGOs processed slowly through the conference centre to be greeted by chants from the throng of activists outside the gates.

Chanting “climate justice now” and “power to the people”, the snaking line of activists still carrying the red ribbons exited the secured area where activists holding fluttering Extinction Rebellion flags were listening to speakers.

John Deman from Devon was in the waiting crowd with his one-year-old son asleep in a back carrier, wearing yellow ear defenders.

“We’ve been coming to different climate negotiations since before the little one was born, so we’re getting used to the results every time being downsized and not as strong as we need. This summit is becoming a joke again, and there’s a real need for them to listen to people like these,” he said, indicating those who had just walked out of the conference.

Moving to the call “we are unstoppable”, activists further up the mixing crowd replied “another world is possible”.