The Taoiseach warned fellow EU leaders on Saturday that even mentioning the new Charter of Fundamental Rights in the EU treaty could have the same legal effect as incorporation in the treaty.
Mr Ahern was among the few who strongly opposed giving the charter binding legal effect, but six leaders spoke in the debate to urge either that it should be referred to in Article 6 of the treaty alongside the European Convention on Human Rights, or that in time it should be incorporated in full into the treaty.
"There is good reason to accept this text as the basis for an eventual European constitution," the German Chancellor, Mr Gerhard Schroder, said, a view echoed by the Italian Prime Minister, Mr Giuliano Amato.
The leaders have sent the text on to the December summit in Nice for formal approval as a political declaration.
In the wake of the Austria crisis, the summit also saw a general consensus emerge on the need to provide a treaty mechanism to forewarn member states about partners' concerns that they may be about to threaten human rights. Commission proposals to this end to amend Article 7 appear likely to be backed at the Nice summit.
The 54-clause charter was drafted by a broadly representative convention over the last nine months to express in a citizen-friendly and "legally neutral" form existing rights ranging from traditional ones like free speech, to general principles covering social policy. It also prohibits human cloning and touches on other aspects of biotechnology ethics.
The Taoiseach's representative on the convention which considered 350 submissions and 1,000 amendments, was the former minister and commissioner, Mr Michael O'Kennedy, assisted by the former legal adviser to the Department of Foreign Affairs, Mr Mahon Hayes. Mr Des O'Malley TD and Mr Bernard Durkan TD represented the Dail.
The charter's ultimate status in treaty terms will be decided later, but the vice-president of the 62-member convention, France's Prof Guy Braibant, told journalists that the charter would have an effect on the law and politics whether or not it was part of the treaty.
"If such a text exists, even if it is not legally binding, courts tend to refer to it," Mr Braibant said. "Magistrates will refer to it and it will inform their jurisprudence." Before it had even been completed it has already been cited four times as a source of European values by the wise men group investigating Austria, he said.
Responding to fears, Irish included, that the charter would create a conflict of jurisdictions with the European Court of Human Rights in Strasbourg, Prof Braibant reassured the leaders that they "had reached a result acceptable to the ECHR".
In the summit debate, according to a diplomatic note seen by The Irish Times, the Finnish Prime Minister, Mr Paavo Lipponen, called for the EU to accede to the European Convention on Human Rights.
The Austrian Chancellor, Mr Wolfgang Shussel, ever-eager to demonstrate his democratic credentials, criticised the charter for its weakness on minorities and language rights and called for incorporation in the treaty.
The leaders of Greece, Italy, Spain, Sweden, Holland and France all supported eventual incorporation although, as the Dutch Prime Minister, Mr Wim Kok, admitted, the language of the text needs refining. In the words of one diplomat "it is too clear to be acceptable to lawyers".
