An outline agreement on the new constitution for the European Union has been formally adopted in Brussels following two days of negotiations between the leaders of the 25 member states led by the Irish presidency.
The deal was struck after Irish officials, including the Taoiseach, Mr Ahern, met the leaders of France, Germany, the Netherlands and Britain to eke out a compromise during six hours of talks today.
The Minister for Foreign Affairs, Mr Cowen, said tonight he believed the past two days of talks had produced "a fair and balanced document" that will "encapsulate the ideals of the people of Europe".
He described the deal as "one of the greatest diplomatic achievements of Irish political history."
The new constitution will replace the existing four EU treaties, simplifying language and modernising law-making methods designed for the original six-nation EU to meet the very different needs of today's 25-nation bloc.
The constitution still has to be ratified by the 25 member states, many of which, including Britain, will hold referendums. If the constitution is not universally ratified, the Nice Treaty will remain in place.
However, agreement on who should succeed Mr Romano Prodi as President of the European Commission looks a long way off tonight. It is undertood this decision has been put off to a later date.
Tensions over the new president were high at the summit last night, threatening a breakthrough today. British Prime Minster Tony Blair's anxiety about Franco-German domination was in evidence when one of his spokesmen reminded reporters today: "We are operating in a Europe of 25 . . . not six or two or one."
He made the comment in response to the French ruling out Briton Mr Chris Patten as a candidate for the European Commission presidency, which is also due to be agreed today. French President Mr Jaques Chirac yesterday said a Briton could not hold the post while Britian remained outside the euro zone and the Schengen open-borders agreement.
"It was unfortunate yesterday that President Chirac chose to attack our position before negotiations had really begun," Mr Blair's spokesman said today.
The British were also unhappy at what they saw as an attempt by the German Chancellor to link the constitution deal to the EC president issue. France weighed in behind the position this morning when a spokeswoman indicated Paris would not compromise on its position on the constitution.
Five hours of talks last night failed to produce consensus on one of at least eight names being mooted for the Commission top job.
The Taoiseach, Mr Ahern, hinted afterwards the matter may be deferred in order to focus on getting agreement on a European constitution. Sources told ireland.comtoday the Irish presidency hoped to agree the constitution by the end of the day, leaving a long evening session to see if a Commission president can be agreed.
Mr Chirac angered the British before yesterday's talks when he ruled out candidates from less integrated states. This also rules out an Irish nomination, though the Taoiseach is regarded as the ultimate compromise candidate.
The French position effectively rules out another leading candidate, Danish Prime Minister Anders Fogh Rasmussen. The outgoing president of the European parliament, Mr Pat Cox, while an outsider, would also be opposed by if the French maintain their position.
But Britain has refused to back the Franco-German candidate, Belgian premier Mr Guy Verhofstadt. Italy, Portugal and Greece are also opposed to Mr Verhofstadt.
Britain's Foreign Secretary, Mr Jack Straw, said: "Guy Verhofstadt was not someone who had the positive support, not just of the United Kingdom but of other member states."
Significantly, Britain is more positive about the constitution despite rejecting the initial draft. London has insisted states retain sovereignty over their own taxation, defence and foreign policy.
Mr Ahern's famed conciliation skills had some effect on the British, "the Irish presidency has done a very good job," the Downing Street spokesman said.
Although the Taoiseach would prefer consensus on Mr Prodi's successor as Commission president, the matter can, ironically, be decided by a majority vote.
Additional reporting: Agencies