Three Fianna Fáil senators today lost the party whip after John Hanafin, Labhras Ó Murchú and Jim Walsh relinquished it over the Civil Partnership Bill.
The three senators have spoken out strongly against the proposed legislation. Mr Hanafin had said they hoped amendments they proposed would be accepted and would “move forward on that basis”.
Mr Hanafin told the upper house the decision had been difficult.
"For some of us it is like being outside the door of the family home."
However, Government Chief Whip John Curran had warned party rules were clear, and that abstaining from votes or voting against the Government position would mean the automatic loss of the party whip.
Tipperary South TD Mattie McGrath recently lost the Fianna Fáil whip after voting against stag hunting legislation.
Addressing the Seanad, Minister for Justice Dermot Ahern said: "The Civil Partnership Bill 2009 is among the most progressive pieces of legislative reform to come before this House in its long history.
"The Bill has the support of all parties. That is significant in that it shows that the measures contained in this Bill have the broad support of the Irish people."
Labour Senator Dominic Hannigan, welcoming the legislation, described it as a "stepping stone to getting equality for gay citizens".
However, Independent Senator David Norris warned the legislation did not grant equality to gay people.
Same-sex couples will be able to avail of legally-binding civil partnerships for the first time from next year after the Dáil passed all stages of the Bill without the need for a vote. The Bill is expected to be signed into law in the autumn.
Under the terms of the Bill, marriage-like benefits will be extended to gay and lesbian couples across a range of areas such as property, social welfare, succession, maintenance, pensions and tax.
