The Seanad has this evening passed a stage of the Civil Partnership Bill without a vote.
Three Fianna Fáil Senators who earlier resigned the party whip are still threatening to vote against it in future votes, however.
Labhrás O'Murchú, John Hanafin and Jim Walshe say the laws will diminish the institution of marriage.
The Bill is now expected to pass all remaining stages in the Seanad in the early hours of tomorrow morning.