Alok Sharma, the former UK cabinet minister who presided over the Cop26 climate summit in Glasgow last year, made a spirited defence of the Glasgow climate pact at the opening of the high-level ministerial roundtable discussions on pre-2030 ambition at Cop27, and warned delegates of the binary choice facing them: “We’ll either leave Egypt having kept 1.5C alive or this will be the Cop where we lose 1.5C.”

He said sticking to the global goal of limiting temperatures to 1.5C above pre-industrial levels had to be a “red line” for all countries at Cop27, and insisted there could be no “backsliding” from it.

He reminded the gathered ministers of what was achieved last year, in very different geopolitical circumstances from the current conference of the parties.

“At Cop26 we did resolve collectively to pursue efforts to limit the temperature increase to 1.5C,” he said. “I have always said what we agreed in Glasgow and Paris has to be the baseline of our ambition. We’ve got to stick to that commitment. We cannot allow any backsliding.”