The Taoiseach, Mr Ahern, warned today claims that the expected referendum on citizenship may fuel racism could become a self-fulfilling prophecy.
Mr Ahern said Opposition parties claims that racist tendencies could surface during the campaign were "a slur on the Irish people".
His comments were made during a Dáil debate on the Government's proposal to amend Article 9 of the Constitution aimed at preventing children born in Ireland of non-national parents from gaining citizenship by right.
He said the Constitution was being exploited by non-national mothers in order to gain residency rights in the EU for their family by establishing citizenship for themselves in Ireland.
The referendum proposal was simply about "stopping the exploitation of our Constitution", he said.
But Opposition TDs claimed running the referendum alongside the local and European elections was a Government attempt to gain votes rather than address an issue which is widely regarded as problematic.
Socialist Party leader, Mr Joe Higgins, said the timing was a cynical act by a "clutch of desperate politicians". He also pointed out that non-national women were preventing the health service from collapse by working as doctors, nurses and nurses aides.
The short time scale for debating the issue and the lack of consultation was a source of widespread annoyance with the Fine Gael leader, Mr Enda Kenny, reflecting the view of many TDs when he called for the matter to be referred to the All-Party Committee on the Constitution.
He said he was willing to address the issue "constructively" but that the Government "have created an adversarial and divisive climate" by failing to consult with all the parties.
"For its own reasons, the Government has chosen to play political games with a very sensitive issue," Mr Kenny said.
The Minster for Justice and Law Reform, Mr McDowell, came in for strong criticism over inconsistencies in his reasoning for holding the referendum.
Green Party leader Mr Trevor Sargent said: "The debate on proposals for change must be on the basis of fact." But the Minister had already conceded he did not have complete figures for births to non-nationals, Mr Sargent pointed out.
Labour leader, Mr Pat Rabbitte suggested changing the Constitution may have little impact on the number of non-nationals giving birth at Irish hospitals because many are from the EU of are in Ireland on work visas or are from wealthy states.
Sinn Féin's Caoimhghín Ó Caoláin noted the "irony" that the Government parties were "keen promotors of the passports-for-sale scheme", which was widely regarded as a scandal.
Mr McDowell had earlier pointed out that he was the minister who had ended the scheme.