The country's Catholic bishops have called on the Government to support a free vote for all TDs and Senators on the Civil Partnership Bill.
The bishops say the Bill seeks to undermine the constitutional protection of the family.
They accused the Government of seeking to give same-sex relationships a standing 'as similar as possible to marriage' in contravention of the Constitution.
However, a spokesman for Minister for Justice Dermot Ahern said that civil partnership is not recognised by the State as marriage and that the core of the measure would not be changed.
The Tánaiste has confirmed the Government expects to have the Bill through the Dáil before the summer recess.
The issue was raised by Sinn Féin's Caoimghín Ó Caoláin, who pointed out that all parties in the Dáil supported the measure.
Mary Coughlan said that the Government intended to bring it to the House after it has been passed by the Seanad.
Fianna Fáil Senators John Hanafin and Jim Walsh had called for a free vote.
Minister for the Environment John Gormley, speaking on RTÉ's News At One, responded to the bishops' comments saying 'he thought we had left the era of church interference behind us.'