A Government backbencher has told the Dáil of her discovery only at the age of 17 that she was adopted.

Labour TD Anne Ferris said "the information came to me in a sudden and unmanaged manner from a sibling".

She told the House: “I cannot begin to explain the destabilising effect of suddenly discovering, on the verge of adulthood, that in many respects that you are suddenly not the person you always thought you were.”

Ms Ferris was speaking as she introduced her Open Adoption Bill, which aims to give access to the natural parents, and other close relatives including grandparents, of a child who is adopted.

She said current law “is like a door that slams shut after the adoption”, locked and sealed to prevent access between the child and birth relatives. “There is not even room to slide a birthday note or a Christmas card under it.”

Speaking of her own experience, Ms Ferris also told of how her own firstborn daughter was given up for adoption.

She said that between 1952 and 1973 more than 20,000 adoption orders were made by the former adoption board. “That is 20,000 children, 20,000 mothers and tens of thousands of other family members separated soon after birth.

“Somewhere lost in those statistics is not just me, but also the young son of Philomena (Lee, whose story became a film), my own firstborn daughter, who was taken from me in 1972 and as I have come to realise, many of my colleagues in the House who were themselves adopted or had children or siblings taken from them and placed into adoption.”

The Wicklow TD said that for all those people the door between them and their birth family members was firmly shut until they were 18 years of age. "For many, despite years of pushing against that door, it has never opened."

Ms Ferris said her own story was one of the lucky ones. “I was reunited with my firstborn daughter after 23 years.” But she added that many people had been in touch with her, mothers and adult children “desperate to make contact yet prohibited from doing so by a closed adoption system that will not grant them access to their records”.

She believed her Bill could have a positive impact for today’s children but much more needed to be done for children who were now adults and the natural mothers “who lost them to adoption many years ago”.

Ms Ferris said the Dáil could start by embracing the Bill’s term ‘open adoption’. “I would like that terms to start altering our collective thinking with regard to reuniting adoptees with their birth families.”

Open adoption placed a child within a broad family network. “It can only be healthier for a child, where a member of their natural family wants to make contact, to have the opportunity to make that contact.”

Minister for Children Charlie Flanagan said he would be very pleased to work constructively with Ms Ferris on her proposals and he referred the Bill to the Oireachtast health and children's committee to examine the Bill.

Mr Flanagan, in his first address to the Dáil as a Minister, said he had made his maiden speech to the Dáil in April 1987 on a private member’s adoption motion. The Minister said he recognised the need for legislation to be updated to reflect both international and domestic developments. “As is often the case with social policy, norms move and change and we as legislators, must respond.”