SDLP leader Mark Durkan has disclosed that his party is still waiting for a reply from Taoiseach Bertie Ahern to a second letter sent to him about concerns over the citizenship referendum in the Republic.
Mr Durkan said the Taoiseach, in his first letter, had addressed some of the concerns that the SDLP expressed.
On this basis he wrote to Mr Ahern again and had a discussion with him when they met last, as well as having talks on the margins of the review talks with Brian Lenihan, the junior minister who is handling the matter.
In addition, Mr Durkan had a recent meeting with the justice minister Michael McDowell and his advisors.
But Mr Durkan has told the Irish News: "We are still awaiting a reply to the second letter we sent to the Taoiseach, because our concerns are not just about the damage which has been done to the Good Friday Agreement.
"It is our belief that no matter what the result is in the referendum, for or against, that the political damage to the agreement has been done.
"The DUP can now cite a precedent which they can say shows you can unilaterally change, vary and alter the agreement, even going to its constitutional core.
"But our concern has also been what would be the possible implications for citizenship of people born in the north in the future? The fact that this new amendment will mean that some aspects of citizenship can be dealt with by legislation in the future rather than constitutional change could maybe mean that the Oireachtas could legislate differently for people born in the south as from people born in the north."
Mr Durkan said the party had been told that there was advice from the Attorney General that could give assurances on the issue.
"We are still awaiting those assurances as we don't have them," he said.
The SDLP leader continued: "In terms of some of the contacts we had recently with the minister of justice and his advisers, this seemed to revolve around the suggestion if we promised that when we received this reply, we would say we were satisfied and endorse the referendum, then we would get the reply.
"But if we don't give that promise, we won't get that reply. That is no basis on which to create confidence and no basis on which any government should be dealing with the issue of citizenship, or in dealing with reasonable and responsible representation such as we have been making."
Asked if this meant that at the moment the SDLP remained opposed to the referendum, Mr Durkan said: "We await the reply. We have never said there is not a substantive issue that maybe does need to be addressed.
"What we offered in the letter we first sent the Taoiseach was a way of addressing it... for instance (by) convening the Forum for Peace and Reconciliation, all the parties north and south. And if we agree that there is something that needs to be dealt with, it can be dealt with, but on the basis of consensus, maximising peoples comfort with it, reducing the amount of concern there is about it.
"We are in the circumstances at the minute where we have replied to the Taoiseach's letter. We were told we would get a reply.
"We can't promise any response to a letter that we have not seen."
Pressed on what advice the SDLP would offer to voters in the Republic on the referendum, Mr Durkan said: "Regardless of what happens, some of the political damage to the agreement has already been done in our view.
"The damage was done in the manner in which the proposal was brought forward in not properly consulting with parties in the north, and going solo to the British government to get the joint declaration with them in relation to this, and in giving the contradictory statements that this was nothing to do with the Good Friday Agreement.
"We are very open with the voters what our concerns have been and we are open about where we are in waiting for a reply from the Irish government."
Sinn Féin president Gerry Adams has also said this week's referendum will have serious implications for the Good Friday Agreement.
He said "anti-peace process elements" had already seized upon it as an example of how the agreement could be tampered with.
Mr Adams said the Irish government was trying to feed into misconceptions and genuine concerns about immigration that do exist in society.
"The referendum is an insult to the Irish people and is an example, once again, of this coalition pushing through serious legislation, without engaging in any sort of debate first," he said.
"This referendum makes a joke of our claim to be Ireland of the welcomes. If it is passed we will be creating a completely unequal society for future generations."
The Sinn Féin president said the party wanted a comprehensive immigration policy that is positive, compassionate, human rights-compliant and anti-racist. The policy must also fully recognise the positive contribution of immigrants to Irish society and to the Irish economy.
Fianna Fail, in its case for a 'yes' vote in the citizenship referendum, said the government was particularly conscious that Article 2 of the constitution had its origins in the British/Irish agreement.
"We wished to maintain the integrity of that agreement in preparing a change to our constitution. We do not wish to be in breach of that agreement which imposed obligations on the two governments," a spokesman said.
"For this reason, both the Irish and British governments have issued an interpretive declaration. It is clear and unequivocal in its terms. It acknowledges that the governments have considered the current effects and consequences of Article 2 of the constitution.
"It states that it was never the intention of either government that persons born on the island of Ireland to parents who did not have, at the date of birth, a sufficient connection with the island of Ireland would be conferred with Irish citizenship."
According to Fianna Fail, they simply want to restore to the Oireachtas the power to legislate on the entitlement to citizenship for children born in Ireland where neither parent is Irish or is entitled to Irish citizenship.
Fianna Fail insisted that if the referendum was passed it would not alter the rights of individual Irish citizens (or those entitled to Irish citizenship) to automatically pass the right to Irish citizenship to their children.
The party also stressed that it would not alter the rights of individual Irish citizens north of the border to automatically pass the right to Irish citizenship on to their children.
The proposal would amend Article 9 of the Irish constitution so that the constitutional entitlement to Irish citizenship to those born in Ireland would be reserved in future to children where at least one parent is an Irish citizen or is entitled to Irish citizenship.