Independent Senator Ronan Mullen has warned the Government and Minister for Justice Frances Fitzgerald that legislation updating family law will destroy their legacy as defenders of children's rights and best interests.

He said there were features of the Children and Family Relationships Bill which were unobjectionable and indeed desirable. “But the legislation contemplates and facilitates a very fundamental attack on a child’s rights by allowing some children to be deprived of the right to be brought up by their own mother and father or, in any event, by a mother and father,’’ he added.

Mr Mullen said important questions merited detailed and careful consideration. “We should be guided by values and sober reflection when faced with making major changes to our society,’’ he added.

He said the Bill would be central to the debate about the marriage equality referendum.

“The timing of this radical Bill today is all about pretending that the change in the constitutional meaning of marriage has no implications for children’s rights to a father and mother,’’ he added.

‘Adult-centred purposes’

“That is yet another way in which children’s rights are being subverted, for other more political, adult-centred purposes.’’

Introducing the Bill, which has been passed by the Dáil, Ms Fitzgerald said the legislation was in the best interests of children. It set out, she said, new and updated provisions on guardianship, custody and access for children living with their married parents, their unmarried parents, with a parent and the parent’s partner or with a grandparent or other relative. She said it also set out the rules under which parentage of a child born through donor-assisted human reproduction might be established. It made provision for a step-parent, a civil partner or a parent’s cohabitant of not less than three years’ duration to apply to the court to become a guardian where he or she had co-parented the child for two years, she added. “The Bill does not alter in any way the parentage of children conceived naturally or through fertility treatment which does not involve the use of donor gametes,’’ she said.

Averil Power, Fianna Fáil, said Irish family law was out of date and did not reflect the diversity of modern families.

"For too long, Irish family law has treated non-marital families as invisible and, as a result, has denied children the legal protection and support they deserve,'' Ms Power added.