The head of the UN Climate Change Secretariat has said a leaked text which appears to undermine the existing Kyoto Protocol and on-going UN climate negotiations in Copenhagen is out of date and is unlikely to constitute the final outcome.
There has been widespread anger among developing nations over the document, which was leaked by The Guardian, a British newspaper and appears to have been drawn up by a small group of rich nations including the US, UK and Denmark.
Speaking on Wednesday, Yvo de Boer said: "That text, and other texts that have been circulating, have not been on the table in a formal sense."
De Boer said that the document was "the basis for discussion among a number of countries, actually a week and a day ago, and have never been tabled in any formal way".
"But I think the [mood] that's out there, people see that as a document that they don't want to be the base for negotiation," he said.
Developing countries have said that the text is part of a plan by rich nations to set unequal limits on carbon emissions in 2050, according to a confidential analysis of the proposals that The Guardian also obtained.
The analysis says that the text worked on by rich nations is a strategy to get developing countries to agree to specific emission cuts, the newspaper reported.
The text seeks to set a limit on developing nations that would not allow them to emit more than 1.44 tonnes of carbon per person by 2050 - while developed nations will be allowed to discharge 2.67 tonnes per head.
Kim Carstensen, head of the climate initiative for the WWF, an environmental group, said: "The behind-the-scenes negotiation tactics under the Danish presidency have been focusing on pleasing the rich and powerful countries rather than serving the majority of states who are demanding a fair and ambitious solution."
Alan Fisher, Al Jazeera's correspondent in Copenhagen, said: "There are two possible reasons for the leak. One is that Western nations were saying - this is our bottom line, these are the draconian measures we are prepared to take to safe-guard our interests.
"Or it could have been the developing nations saying - if you are even considering anything like this, there is going to be a revolt you have never seen the like of before.
"The Danes are not denying that the document exists, but they are saying it doesn't carry any official weight at all."
The draft text, which was leaked on Tuesday, is also understood to call for handing control of climate change finance to the World Bank.
Waldon Bello, the director of "Focus on the Global South", a non-governmental organisation specialising in policy research, said that the text was evidence of a "betrayal" on the part of rich nations.
"This is a terrible document - the idea that there would be differential limits put on emissions to favour the north [and] the fact that there would be abandonment of the only legitimate framework, which is the Kyoto Protocol," he said.
"This is not what developing countries were expecting. They were expecting the north to make a serious offer and this is definitely not a serious offer at this point in time. This shows that there is just no 'give' when it comes to the north."
On the same day that the text was leaked, a senior Chinese negotiator told reporters in Copenhagen that the US's emissions target was not notable, that the EU's was not enough, and that Japan's came with impossible conditions.
He also criticised talk of developed nations contributing $10bn annually to poor countries to help them cope with climate change, saying that more money is needed.