Ambassadors from a core group of member countries were trying to reconciledifferences on multiple issues in the hope of delivering a comprehensive document for the world leaders to ponder and hopefully adopt.
The text, which still had to be translated into multiple languages, should have been finalised days ago.
What was clear by yesterday, however, was that whatever does emerge from the three-day meeting - the biggest such gathering of world leaders under a single roof - it will fall far short of what was originally intended and will be a disappointment to many countries and to non-governmental groups.
Sources said that all sides had more or less agreed language for measures to combat terrorism, create a "peace-building commission" to help countries emerge from conflict and on creating a new Human Rights Council.
Differences remained elsewhere, especially on non-proliferation. Even where the language had been agreed upon, the document fell far short of what was originally proposed.
Disappointment will be very keenly felt by the secretary general, Kofi Annan, who kicked off the process of distilling proposals for this summit two years ago and produced his own blueprint in March, called "In Greater Freedom". It amounted to a bold manifesto for the revival of the body he leads and the reinvigoration of the principles of multilateralism, so damaged by the US invasion of Iraq.
The proposed summit agenda was also tacitly conceived as a grand bargain between the developing and developed nations. The latter would win important commitments on reforming the UN - with Mr Annan given much of the authority to implement the changes - and on focusing the body more on security and terrorism matters. In return, developed nations would make firm promises to increase overseas aid.
That bargain and almost everything else proposed by Mr Annan, who had the strong backing of Britain, has now been largely picked apart. Famously, the United States ambassador to the UN, John Bolton, made no fewer than 750 proposed amendments to the text. Many details of the document irked Washington, such as references to the International Criminal Court and to the Kyoto protocol on climate change.
More fundamentally, however, America wanted the summit conclusions to represent a declaration of intent rather than an operational document that would legally bind the US and other governments to the implementation of all of its contents.
At the same time, several other countries have proved at least as obstructive as the US on many issues. Language on terrorism has been compromised by Arab reservations, while one measure that the US warmly supported - replacing the discredited Human Rights Commission in Geneva with a new body, the Human Rights Council - has also stumbled.
The leaders will probably agree on the principle of creating the new body, but will leave crucial details of how it will be set up and who will sit on it until later.
Diplomats were not sure last night what was likely to happen next. Most hoped that the negotiating diplomats would eventually work outan agreed, if thoroughly diluted, text just in time for translators to work on it overnight. At least something should be ready for the leaders when they file into the General Assembly Hall this morning.
Alternatively, it remained possible that the business of negotiating the summit outcome would drift into today, falling into the laps of the leaders themselves. That was never the plan, but the very presence of so many leaders in town with no document to agree upon "might really focus minds ", one Western diplomat said.
It may be that Mr Annan was too ambitious in his original agenda. "If things collapse it will be because the traffic was too heavy for the road to bear," Munir Akram, the ambassador at the UN for Pakistan, said. His country has been blamed for sabotaging efforts to agree on the expansion of membership of the UN Security Council. Pakistani resistance was fuelled by a desire to keep India off the council.
The ambassador of Mauritius, Jagdish Koonjul, said it was inevitable that whatever emerges it will have been reduced to the "least common denominator".
Mr Annan's camp was trying to put the bravest face on the continuing chaos. His chief of staff, Mark Malloch Brown, said some agreement would be better than none.
"There's a threshold where we always knew we wouldn't get the full loaf, " he said. "We've got to start counting slices. Half or more will do at this stage."
The policy battlegrounds
Expect language condemning all terror acts and killing of innocent civilians and non-combatants for political purpose. But it will have been diluted. Arab states demanded paragraph giving exemptions in cases of armed struggle against illegal occupations. (Think Palestine and Israel.) Text will say terrorists acquiring unconventional weapons is greatest threat to world peace. US resisting all reference to nuclear powers taking steps to disarm.
HUMAN RIGHTS COUNCIL:
Western nations supported Annan's plan to disband Human Rights Commission in favour of Human Rights Council. The idea likely to be endorsed, but efforts to agree details have been abandoned. The UK and US want members to be elected by two-thirds majority of General Assembly to ensure governments with poor human rights records stay off it. Cuba, North Korea and others are blocking.
Western nations anxious to give Annan free hand to begin internal reform to increase accountability, financial auditing, external monitoring and so on. Developing nations are resistant because they want authority to remain with General Assembly. All attempts at agreement on expanding Security Council have been deferred to later date.
Draft text includes timetables for halving poverty around the world, cutting maternal deaths, halving the spread of AIDS and increasing development aid. Restored are references to the Millennium Goals set in 2000 and calls on developed nations to increase aid levels to 0.7 per cent of GDP, but US does not want these to be binding. Most of this agreed in other forums. US resisting calls by developing nations for language on reducing trade barriers.
Aimed at helping nations emerging from conflict. It is agreed it should be established. The US wants Security Council to have control over the body, while developing countries want it to report to General Assembly.
RESPONSIBILITY TO PROTECT:
Leaders are expected to adopt language for the first time allowing for intervention in cases of ethnic cleansing and genocide. However, India wanted vaguer language about guarding against genocide.Reuse content