The deal finally hammered out had been expected to commit countries to deep cuts in carbon emissions. In the end, it fell short.

Instead, a draft agreement put forward by China - and backed by Brazil, India and African nations - commits the world to the broad ambition of preventing global temperatures from rising above 2C.

Yesterday some delegates openly attacked China.

Asked who was to blame for blocking the introduction of controlled emissions, the director-general of the Swedish Environmental Protection Agency, Lars-Erik Liljelund, replied: "China. China doesn't like numbers."

The accord was formally recognised after a dramatic all-night plenary session, during which the Danish chairman was forced to step aside and British Climate and Energy Secretary Ed Miliband salvaged the deal just as it seemed on the verge of rejection.

The tumultuous events concluded a fortnight of fraught and sometimes machiavellian negotiations that saw a resurgent China link forces with India, Brazil and African nations to thwart efforts by rich nations to steamroller through a treaty suiting their interests.

Although hailed by United States President Barack Obama, the deal has been condemned by activists and non-government organisations, while the European Commission's President, Jose Manuel Barroso, admitted he was disappointed after EU attempts to introduce long-term targets for reducing global emissions by 50 per cent by 2050 were blocked.

Nnimmo Bassey, chairman of Friends of the Earth International, said: "This accord is not legally binding, it's a political statement. Without legally binding commitments, there is no way to be sure it will be attainable. This is a disaster for the poor nations."

Yesterday Mr Miliband was being credited with helping to rescue the summit. He had been preparing to go to bed at 4am, after the main accord had been agreed on, only to be called by officials warning that several countries were threatening to veto it.

He returned to the conference centre in time to hear Sudanese delegate Lumumba Di-Aping comparing the proposed agreement to the Holocaust. He said it "asked Africa to sign a suicide pact, an incineration pact, in order to maintain the economic dominance of a few countries".

A furious Mr Miliband dismissed Mr Di-Aping's claims as disgusting. This was "a moment of profound crisis", he told delegates. The proposed deal was by no means perfect "but it is a document that in substantive ways will make the lives of people around this planet better because it puts into effect fast-start finance of US$30 billion ($42 billion), it puts into effect a plan for US$100 billion of long-term public and private finance". Delegates then agreed to the deal.

Yesterday, leaders of non-government organisations united in condemnation.

"We have no choice but to forge forward towards a legally binding deal in 2010," said Oxfam International spokesman Robert Bailey. "This must be a rapid, decisive and ambitious movement, not business as usual."

Alden Meyer, of the Union of Concerned Scientists, said: "It clearly falls well short of what the public around the world was expecting.

"It's clearly not enough to keep temperatures on a track below 2C."

Christian Aid's senior climate change advocacy officer, Nelson Muffuh, was also scornful. "They came to play hardball. Lives will be lost as a result."