A representative from Sudan for a major bloc of developing nations on Saturday called a draft climate deal in Copenhagen the "worst in history" and hinted it may try to block it.
Lumumba Stanislas Dia-ping of Sudan, chairing the Group of 77 and China bloc of 130 poor nations, accused
the United States and host Denmark of trampling on the rights of poor countries.
"Today's events really represent the worst developments in climate change negotiations in history," Dia-ping told reporters.
"The deal locks developing countries and the poor of developing countries into a cycle of poverty forever," he said.
But it remained to be seen if he would have all developing nations on board as leaders of key nations including China, India, Brazil and South Africa had negotiated personally with US President Barack Obama.
The 194-nation summit was due to meet in the early hours Saturday to review the deal negotiated among major wealthy and developing nations.
Under the rules of the UN Framework Convention on Climate Change, which leads the summit, any agreement has to be approved by consensus.
Dia-ping said Sudan did not agree with the consensus but declined to say clearly whether the delegation would try to block it.
Dia-ping has complained throughout the conference that major countries had thrashed out details behind closed doors and not in the full session, which was dominated by speeches from leaders.
"President Obama, acting the way he did, definitely eliminated any differences between him and the Bush presidency," Dia-ping said.