It would take a century to fill Lansdowne Road stadium with the people who were supposed to be causing the citizenship difficulties, it was claimed yesterday.
Green Party president Mr John Gormley said that "we have now been told that the number of people affected is 442. That does not represent a crisis.
"At that rate it would take 100 years to fill Lansdowne Road to capacity if we were to fill it with the people who are supposed to be causing this problem."
The Dublin South-East TD said his constituency colleague, the Minister for Justice, was engaging in opportunism.
Mr McDowell had been opportunistic in his criticism of Fianna Fáil at the last election, but "while having a go at Fianna Fáil might be regarded as opportunistic, its effect is not permanent or pernicious.
"This latest attempt by the Minister disturbs me greatly because the long-term effects of this political manoeuvring could be quite profound."
Mr Gormley said the Minister was only too aware of racial tensions in Irish society.
"However, rather than trying to calm the situation as a Minister charged with justice and equality should, he has chosen instead to mine what he knows to be a rich electoral vein. It may yield electoral results but at what price?
"I do not believe Minister McDowell is a racist. In his more enlightened moments he could well give a passable impression of a liberal" but "by rushing this legislation through the House the Minister is allowing ruthless political ambition to cloud his moral judgment".
The Minister for Social and Family Affairs, Ms Coughlan, said the amendment "is most certainly not racist. It will apply even-handedly to the children of all non-nationals irrespective of colour, ethnicity or any other criterion on which racism is based."
Ms Fiona O'Malley (PD, Dún Laoghaire) said that Opposition deputies had called for a full debate on immigration policy. "The holding of the referendum will give this opportunity if the referendum is passed by the people."
She also defended it as a "wise decision because participation in the electoral process is most important. We are guaranteed a higher level of participation in the referendum if voters are also coming to the polls for another election."
Mr Charlie O'Connor (FF, Dublin South West) said the electorate was expressing "strong support for this legislation". He pointed out that "regardless of whether we like that or wish to reflect other views in this House, that is what people are saying to us".
Mr Arthur Morgan (SF, Louth) said the referendum "will completely eliminate the basis of Irish citizenship as it has existed since the foundation of the State in favour of a strict bloodline criterion".