Minister for Justice Dermot Ahern has published the Civil Partnership Bill, which gives people in long-term and same-sex relationships many of the rights of married couples.
The Bill will allow same sex couples to register their civil partnership for the first time and it also contains succession rights, protection of a home that couples share, plus maintenance rights in the event of a separation.
On registration, civil partners will be treated in the same way as spouses under the tax and social welfare codes.
The Bill also gives financial protection to a dependent person of an unmarried opposite sex couple or an unregistered same sex couple at the end of a long-term cohabiting relationship.
Mr Ahern said that while the Bill did not legislate for marriage, it struck a fine balance for all concerned.
He added the Bill could not stray into the area of marriage because of the Constitution.
Reacting to Green Party suggestions that the new Bill does not go far enough, the Minister said it had been approved by a cabinet of which the Greens are members.