People Before Profit TD Richard Boyd Barrett said while his situation as an adopted person has "turned out to be a lucky one", this has not been the case for "many people".
The Dún Laoghaire TD told the Dáil on Thursday his birth mother was able to find him "with some considerable difficulty" and he had a "wonderful family", with a "happy outcome", but others have "suffered terribly" in different ways, including abuse.
Mr Boyd Barrett was speaking during a debate on the Birth Information and Tracing Bill, which will allow people to access full birth certs and other information.
Adoption rights campaigners and opposition politicians have criticised a requirement for adopted people to take part in information sessions, in cases where their natural parents have said they do not want to be contacted, before they can access records about themselves.
Campaigners have claimed that the information session condition means they do not have unrestricted access to records like birth certificates.
Mr Boyd Barrett described the requirement of information sessions if the mother expresses a no-contact preference as “not acceptable” , “unnecessary” and “insulting”.
“It assumes, which one should not assume, that adoptees necessarily want contact. They don’t necessarily want contact,” he said.
“You’re bringing something into the equation when simply people are looking for their birth information, looking for medical information, looking for the gaps in our history and our heritage and their identity, things that have been taken from them that they are entitled to under GDPR, that they are entitled to morally.
“Why would we then import into that the assumption that they need to be lectured about seeking to contact their birth mother or their birth parents. Why would we do that?”
He said survivors and adoption groups have requested there be a stakeholder group to oversee the implementation of the legislation as well as on ongoing review which they could also provide input to adding that this proposal “needs to be taken on board”.
Mr Boyd Barrett also said the bill “does almost nothing” to enhance the “very limited rights” of mothers to access information about children they were “effectively forced” to give up for adoption.
“As I understand the bill, the only thing this additionally does is allow them to get that information if their child died in the institution. That’s just not good enough,” he added.
Fianna Fáil TD Jim O'Callaghan said two conflicting fundamental rights were being dealt with in the legislation; the right to identity and the right to privacy.
"At some stage this legislation is going to be appraised by a court. When that court comes to look at this legislation, it is going to examine the way the Houses of the Oireachtas balanced these rights and how weight was given to the right to identity, but also to the right to privacy," he said.
The Dublin Bay South TD said the inclusion of information sessions in the legislation would recognise that the Oireachtas had taken into account the right to privacy.
Minister for Children Roderic O'Gorman said it was the Government's belief that the information sessions would be the best way to ensure that the constitutional right to privacy is "sufficiently present" in the legislation and would significantly reduce the risk of the Supreme Court at some point saying the legislation was "unconstitutional".
Mr O’Gorman said there were legal challenges to the issuing of information in the past and it was “important that we get that balancing of rights correctly”.