Seven judges of the Supreme Court have begun hearing an appeal by the State against a landmark decision on surrogacy rights.
Last year, High Court judge Mr. Justice Henry Abbott ruled that the genetic mother of twins born to a surrogate can legally be described as the children's mother on their birth certificates.
The State is arguing that the presumption in public law is, and always has been, that the woman who gives birth to a child is by definition the mother of that child.
Opening the appeal, barrister Michael McDowell SC described the High Court decision as 'radically wrong'.
He is arguing that a law based on genetics, in which motherhood could be ascribed to the donor of an ovum, could have 'massive consequences' for succession, citizenship and criminal law.
He has also questioned whether the High Court judgment means that a woman who is considered by the Constitution to be the mother of an unborn child could cease to be the mother after the birth.
"Mere donation of genetic material does not confer the Constitutional status of parenthood or natural rights" said Mr McDowell.
He has also argued that parenthood cannot be conferred by agreement.
The Supreme Court has been told that it is a matter for the Oireachtas whether to change the law. The appeal is due to last 3 days.
