Thursday, 10am (Danish time)
The extraordinary story of the final moments of the Copenhagen climate summit, which continued long into the night, began on Thursday morning, when Gordon Brown met the prime ministers of Australia and Denmark, Kevin Rudd and Lars Rasmussen. The trio agreed to divide up their duties and discussed how they would persuade the rest of the world's leaders to reach an accord.
Mr Brown and Mr Rudd also convened a group of six countries eager to reach a climate deal, which later become known as the "Circle of Commitment". It included Mexico's President Felipe Calderon, Norway's Prime Minister Jens Stoltenberg, Bangladesh's Prime Minister Sheikh Hasina Wazed and Meles Zenawi, the Prime Minister of Ethiopia and the chief negotiator for the union of African nations.
That night, Mr Brown held a crucial meeting with the Chinese Premier Wen Jiabao, which went well. As he departed for the state dinner hosted by Queen Margrethe of Denmark at Christiansborg Palace, the Prime Minister was upbeat, and his advisers found time to go for a steak before rejoining him at the Bella Centre, where a crucial group discussion had been scheduled. Mr Brown sat beside the US Secretary of State Hillary Clinton at the session, which included 26 world leaders from developed and developing countries, including Gabon, Papua New Guinea and Mexico.
As Thursday turned into Friday, Mr Brown's aides posted a message on the Downing Street Twitter page: "1am – late-night haggling with 30 leaders. Tough, but we're determined to crack it."
After good progress had been made, Mr Brown and many of the other leaders retired to bed. The Secretary of State for Energy and Climate Change Ed Miliband was chosen to continue the talks through the night. But over the next few hours, things started to go wrong, and when the meeting finished at 6am, the discussions had become bogged down by "procedural objections" raised by China, India and Sudan.
When the Prime Minister was awoken at 6am and informed that things were not looking good. He immediately began making frantic phone calls, but at 9.30am a member of his staff said there was now "a risk of getting nothing" by the end of the day.
Half an hour later, an emergency meeting was called and Mr Brown sat down beside the newly arrived US President Barack Obama. Joining them were about 20 leaders and ministers, including French President Nicolas Sarkozy, German Chancellor Angela Merkel and Japan's Prime Minister Yukio Hatoyama. In what was perceived as a significant diplomatic snub, China sent their vice foreign minister, He Yafei. The leaders were guided through the text of a draft agreement, but according to one witness, the Chinese negotiators frustrated the process by intervening "after every point of substance". Mr Brown's aides briefed journalists that he took on a central role, gesturing to each leader in turn and asking them: "What do you want to say?" They claimed: "Any impartial observer would come in and think Gordon was chairman."
As the leaders talked, the conference centre's main plenary room became more crowded as the rest of the world waited for the meeting to end. Press briefings for the African countries and Brazil were cancelled, but still the leaders did not arrive.
The emergency meeting finally finished at 11.30am, when an hour-long recess was declared. Nine minutes later, Mr Rasmussen entered the plenary hall, and had to apologise twice for the delay before the meeting began at 11.49am, almost two hours later than planned. After the Danish Prime Minister's speech, and despite the international tensions clearly simmering beneath the surface, the UN Secretary-General, Ban Ki-moon, headed for the stage and said: "Never has the world united on such a scale."
In his speech, Mr Wen insisted that his country was "fully committed to reaching" its voluntary targets on reducing carbon emissions, but in a sign that the emergency meeting had done little to improve the fraught relations between China and the US, Mr Obama made a suggestive last-minute alteration to his speech as he walked between the emergency meeting and the plenary room.
He also criticised China's reluctance to be transparent about its actions: "I don't know how you have an international agreement where we are all not sharing information and ensuring we are meeting our commitments. That doesn't make sense. It would be a hollow victory." Furious at this remark, which he perceived as a slight on his nation's honesty, Mr Wen returned to his hotel and instructed low-level delegates to resume negotiations.
Gordon Brown and Barack Obama returned to a private session in a final attempt to put pressure on China and salvage a deal. "The prospects for a deal are not great. There is a risk of failure," a UK official admitted. The photograph of smiling world leaders was supposed to take place at noon; the announcement that it had been indefinitely delayed did not surprise anyone. An hour later, Venezuelan President Hugo Chavez attacked the US, calling it a "Yankee empire" which would "disappear through the back door" after jetting in at the last minute and getting the deal it wanted.
Later, Mr Wen and Mr Obama managed to hold a bilateral meeting, which a US official said had moved them a "step forward". At 1.30pm, Downing Street said the delegation had "broken into small groups to try to break [the] log jam".
The tense US-China relations came to a head mid-afternoon, when Mr Obama and Mrs Clinton were left sitting in a meeting with three low-level Chinese delegates. According to a source, the US President clearly regarded Mr Wen's absence as a major diplomatic insult, and snapped: "It would be nice to negotiate with somebody who can make political decisions."
The EU environment commissioner, Stavros Dima, told Reuters that the UN had asked all of the leaders to stay overnight in an attempt to hammer out a deal. "I cannot imagine 120 leaders going back to their countries with empty hands. Everyone expressed commitment to fight climate change," he said.
But Downing Street said it was unaware of any such proposal, a UN spokeswoman later issued a denial. By this point, rumours had started to circulate about a new draft agreement called the Copenhagen Accord, which crucially dropped the deadline of the end of 2010 for reaching a legally binding treaty.
Mr Miliband announced that the talks had broken up for a recess. Shortly afterwards, an exhausted-looking Mr Brown told the British media that there was "still a lot of work to be done". At 6pm, Downing Street tweeted: "Tough talks continue. Small minority holding out against consensus."
Mr Obama attended only his second meeting of the day with Mr Wen. He was forced to leave the Bella Centre and drive to the Chinese Premier's hotel.
It emerged that the Russian President Dmitry Medvedev had left the summit to make a scheduled visit to Kazakhstan, as the remaining delegates read through a fourth draft of the text.
Reuters reported that Mr Obama had reached a "meaningful agreement" with China, India and South Africa. It quoted a US official who describes it as a "historic step forward", but not sufficient to fight climate change. At 10.45pm, Downing Street tweeted: "It has been an exhausting day. But we are almost there."
Mr Obama officially announced that the US has brokered an accord with China, India, South Africa and Brazil, which included a means for each country's greenhouse gases to be monitored. But he added that securing a binding agreement was not achievable, describing a "fundamental deadlock in perspectives" between big, industrialised countries and developing nations. Conversely, China spoke of a "positive" result adding that "all should be happy". As the curtain fell on the summit, an environmental backlash began. The World Development Movement described the event as "devoid of any real content".
Lumumba Di-Aping, chairman of the G77 group of developing countries, described the deal as "extraordinarily flawed". It was left to the world to debate the outcome into the early hours of this morning.