The leaders returned to the Justus Lipsius building in the EU quarter of central Brussels at 10 a.m. yesterday, some a little bleary-eyed after Thursday's late-night talks on the next Commission President, writes Denis Staunton in Brussels.
Before turning to the constitution, they rattled swiftly through 25 pages of a joint statement on the EU's regular business, including foreign policy, the fight against terrorism and Europe's economic agenda.
The mood was a little fractious when the constitutional negotiations resumed around noon, and the Taoiseach warned leaders that they could not expect to leave Brussels with all their wishes fulfilled.
"I have no magic wand to give you all you want. We need compromises, but we don't want a dog's dinner of a document," he told them.
Overnight, the Presidency prepared a new compromise text covering the most contentious issues, including the three institutional questions at the heart of the negotiations.
The new paper defined a qualified majority as 55 per cent of member-states comprising at least 65 per cent of the EU's population. No measure could be blocked by fewer than four countries.
The new draft included, in square brackets, a proposal that abstentions should not be counted in calculating the total number of member-states and of population.
The text amended an earlier Presidency draft to state that, from 2014, the Commission would be reduced in size so that two-thirds of member-states would be represented on it during each five-year term. It added a declaration that the Commission should take all necessary measures to ensure that the "political, social and economic realities" in all member-states are taken into account, even when they are not represented in the Commission.
The draft proposed raising the minimum number of MEPs sent by each country to six, but limiting the size of the European Parliament to 750. It said that no member-state should have more than 96 seats in the Parliament, a potentially controversial proposal given that Germany currently has 99 MEPs.
The Czech prime minister, Mr Vladimir Spidla, was the first to speak and he made clear immediately that he was unhappy with the formula defining a qualified majority. In common with Austria, Cyprus, Estonia, Greece, Finland, Hungary, Latvia, Lithuania, Malta, Portugal, Slovakia and Slovenia, the Czech Republic wanted a qualified majority to be defined as at least 58 per cent of member-states representing at least 65 per cent of the EU's population.
This group of small countries also wanted a blocking minority to consist of at least five member-states. Mr Spidla urged his fellow leaders to bear in mind the fact many countries, including his own, would hold referendums on the constitution.
The French president, Mr Jacques Chirac, said it was imperative that the leaders agreed a final text yesterday, adding that the consequences of failure should not be underestimated. Mr Chirac rejected the small countries' call for a new formula on qualified majority voting that would narrow the gap between the percentages of population size and of member-states. He said that France accepted the Presidency proposals on the Commission and the European Parliament.
Latvia's Mr Indulis Emsis said that a compromise on the definition of a qualified majority had to be found, but added that the Irish Presidency clearly had not found it yet.
Poland's Mr Marek Belka referred to a proposed declaration promising to take note of the opposition of at least 30 per cent of the EU's population or 40 per cent of member-states and to seek to address such concerns.
He wanted the declaration to be incorporated into the treaty and to be made permanent, abolishing a 2014 sunset clause proposed by the Presidency. Mr Belka said that Poland could accept all other Presidency proposals, but he noted that no changes had been suggested to the Preamble, into which Warsaw had hoped to insert a reference to Christianity.
Hungary's Mr Peter Medgyessy said that each country should continue to nominate a member of the Commission until EU leaders agreed unanimously to change the system.
Germany's Mr Gerhard Schröder said that the Presidency proposal represented a huge compromise on the Convention draft, but that Germany would accept the new draft as it stood. He added that Berlin was content to lose three of its seats in the European Parliament.
The Taoiseach defended the Presidency's definition of a qualified majority and told the small countries that the proposal on the Commission represented an improvement on Nice and guaranteed full equality between Germany and Malta. He added that a better deal was unlikely to become available in 2014.
Over lunch, the leaders discussed non-institutional issues, a discussion that saw some sniping between Mr Chirac and Britain's Tony Blair. Mr Blair insisted that, by demanding extra wording on the scope of the Charter of Fundamental Rights, he was not seeking to water it down but to introduce legal certainty and clarity.
After lunch, the meeting broke up and Mr Ahern conducted six hours of bilateral meetings in the Presidency's office opposite the conference chamber. During these discussions, Mr Bobby McDonagh and his team from Iveagh House drafted new versions of the most contentious articles in the treaty.
One participant described the bilateral meetings as tough, but Mr Chirac took the opportunity offered by his meeting with the Taoiseach to praise the conduct of the Irish Presidency. "My officials have seen many Presidencies. None has equalled this one," he said.
By 8 p.m., word seeped out from the fifth floor of the Justus Lipsius building, where the Taoiseach was holding his consultations, that a deal was imminent.
A final text addressed many of the issues raised during the day without altering the basic institutional structure proposed. Thus, a qualified majority was now defined as at least 55 per cent of the member-states, "comprising at least 15 of them" and representing at least 65 per cent of the EU's population. The requirement of 15 member-states effectively raises the population threshold, at least until the EU takes in new members.
On the Commission, the final draft stated that, from 2014; "the Commission shall consist of a number of members, including its President and the Union Minister for Foreign Affairs, corresponding to two-thirds of the number of member-states, unless the European Council, acting unanimously, decides to alter this figure".
This rendezvous clause removes the automatic nature of the reduction in the Commission's size, but the requirement of unanimity ensures that the change is almost certain to go ahead. Further compromises focused on a dispute over the Stability and Growth Pact, economic policy co-ordination transport and cohesion funds.
The deal was accepted shortly after 10.30 p.m. and the Taoiseach received a standing ovation from other EU leaders. Exhausted Presidency officials expressed delight at the outcome, but celebrations had to be postponed while EU leaders returned to the table to work out how to solve their next big problem - choosing a successor to Romano Prodi as Commission President.