Generally, it’s been women in Fianna Fáil who have led the charge: Averil Power now, Maire Geoghegan-Quinn on not going for a higher age of consent in 1993, Mary O’Rourke on the Unfair Dismissals Act.
A notable exception would be Mary Coughlan when, after her Department of Social — umm was it Protection or Welfare? — was forced to grant a free travel pass to a gay couple under equality legislation, she changed the law in order to prevent any more same-sex couples from getting one (thereby preventing hordes of elderly gay couples from bankrupting the State, one presumes).
Dermot Ahern can claim credit for the civil partnership legislation but also changed what started out as a Civil Partnership Bill into the Civil Partnership and Certain Rights and Obligations of Cohabitants Act. On the equality legislation, John O’Donoghue took up the mantle after the Supreme Court rejected Mervyn Taylor’s Employment Equaliy Bill and Equal Status Bill, and re-introduced Taylor’s bills with tweaks to keep their lordships happy.
Éamon Ó Cuív was the Minister for Social Protection in June 2010 when the State dropped its appeal to the Supreme Court against the finding of incompatibility of the regime that prevents trans people’s true gender being recognised. I would love to see the cabinet papers to know if that was him or the Attorney General.