For weeks the Green Party has argued that central and eastern European public opinion backed its call for a No vote in the Nice Treaty referendum.
Yesterday it ran into Hungarian-born Ms Abigel Sheridan.
Upsetting the Green Party's script, Ms Sheridan, who has lived in Ireland for four years following her marriage to an Irishman, expressed "deep hurt and dismay" at the party's opposition to the treaty.
In an open letter, she said it was "unimaginable" that any party aware of the struggle of the EU candidate countries after 1990 "would seek to betray us in this way.
"Yet, this is what is happening here today," she declared.
The 12-year effort to qualify for EU membership, which offered the best opportunity to protect the candidate countries' security and to improve their economies, has not been easy, she said.
"Against this background, it is easy to understand the sense of betrayal we will feel if Ireland, and Ireland alone, denies us the opportunity of membership in 2004," she declared. And she went on: "The Green Party is dishonest when it says that it supports enlargement, but opposes the Nice Treaty. No one, including the Greens, knows how an enlargement to accommodate 10 states can take place without Nice.
"It cannot take place by 2004, that much is clear. If Ireland rejects Nice, the negotiations to find a solution to enlargement, if there is a solution, will be complex, difficult and prolonged. One thing is clear, whatever views Ireland may have on arrangements for enlargement in the future, these will receive little sympathy from the existing member-states and none whatsoever from the candidate countries.
"They will feel betrayed by a country which they saw as an inspiration and role model for the kind of life they could aspire to in the future. Ireland will be isolated for the first time since it joined the EU," she wrote.
Questioning her right to speak for all citizens in central and eastern Europe, the Green Party leader, Mr Trevor Sargent and Dublin MEP Ms Patricia McKenna repeatedly denied that they were opposed to enlargement.
The Green Party's director of elections, Mr Paul Gogarty TD said: "The biggest lie of this campaign has been that a rejection of the Nice Treaty will somehow prevent enlargement."
Insisting that the Amsterdam Treaty could be used to accept all of the qualifying member-states, he said a rejection of Nice would delay enlargement only if existing EU members wanted it to do so.
"It is up to the governments of the EU member-states to decide whether to selfishly prevent enlargement because Nice is rejected, or to proceed as planned under Amsterdam," said the Dublin West TD.
Quoting from a series of senior European Union figures, Ms McKenna said it was clear that they knew that Amsterdam did not limit the number of new members to five.
And she said that the Polish Prime Minister, Mr Leszek Miller, voiced his belief that enlargement would not be scuppered by an Irish No. "A solution will be found, he said," declared Ms McKenna.
