Mr Ahern will now attempt to nudge EU leaders towards compromise on the big constitutional issues, writes Denis Staunton, European Correspondent
After the flag-raising and fireworks to welcome 10 new countries into the EU, the Taoiseach set to work yesterday on the most delicate phase of negotiations on the constitutional treaty.
A meeting with Slovenia's Prime Minister, Mr Anton Rop, marked the start of an intensive round of talks that will take Mr Ahern to 23 European capitals during the next month.
Mr Ahern said after yesterday's meeting that the treaty is unlikely to contain an explicit reference to God despite pressure from a number of member-states and from religious leaders, including Pope John Paul II.
"I do not think we will get a reference to God. I think the wording that is there now will probably stay the same. There might be some change, but I do not think it is going to change substantially.
"I know some countries are continuing to keep the issue open, but it is not something that has been raised much with me in recent weeks."
The latest draft text of the constitution's preamble refers to "religious values", but does not single out the Christian tradition, a reference that has been opposed by France and Belgium.
At a meeting in Croke Park tomorrow, senior officials from all 25 member-states will seek to isolate the remaining outstanding issues in the constitution, and approve compromises apparently agreed towards the end of the Italian presidency.
The most controversial issues, such as a proposed change in the way member-states vote in the Council of Ministers and a possible reduction in the size of the Commission, will be left to the final stage of negotiations.
During his tour of capitals, however, Mr Ahern will attempt to nudge leaders towards compromise on the big issues, which also include proposals to abolish national vetoes in a number of policy areas.
Mr Ahern will also take soundings on possible candidates to succeed Mr Romano Prodi as Commission president. Sources close to Mr Ahern say that he is starting with "a blank sheet", and that no front-runner has emerged.
Leaders discussed the appointment informally during Saturday's dinner at Farmleigh, partly in response to press reports suggesting that the External Affairs Commissioner, Mr Chris Patten, could be available. Mr Patten told the BBC that he would need a lot of persuading to take the job, but he did not rule it out.
As one of the most articulate and impressive members of the Commission, Mr Patten is an attractive candidate whose appointment might also help Mr Tony Blair to win a referendum on the constitution.
Senior French sources, however, described Mr Patten as "a non-starter", and some officials suggested that Britain's failure to adopt the euro could count against him.
Mr Patten belongs to the centre-right, which has laid claim to the leadership of the next Commission, and threatened to block a centre-left candidate in the European Parliament. Other conservative contenders have dropped out of the race in recent weeks, and Luxembourg's Mr Jean-Claude Juncker, who was long seen as a favourite, has promised to stay in Luxembourg if, as expected, he wins a general election on June 13th.
Officials said that Belgium's Prime Minister, Mr Guy Verhofstadt, indicated over dinner on Saturday that he would be willing to succeed Mr Prodi if called upon.
Senior Irish presidency sources suggested that if France, Germany and Britain agree on a candidate, other member-states are likely to fall into line. "If those three agree on someone, that person will get the job," one official said.
The president of the European Parliament, Mr Pat Cox, who is popular in the new member-states, retains an outside chance of getting the top job. Mr Cox will declare on Wednesday if he intends to run in next month's European elections.
He is expected to step down, and to spend the next month campaigning to persuade the Taoiseach to nominate him as Ireland's next EU commissioner. The openness of the race for Commission president means, however, that the support of a number of the EU's small member-states could create a momentum behind Mr Cox that could make him a serious contender when Mr Prodi's successor is chosen next month.