Gender neutral birth certificates which list “parent one” and “parent two” as alternatives for mother and father should be introduced in the UK, the Court of Appeal has heard.

The Lord Chief Justice of England and Wales, Britain’s most senior judge, today heard the case of transgender father Freddy McConnell who last year lost a legal fight against the Government’s “outdated” birth registration system.

Mr McConnell, who was born a woman but later legally transitioned to a man, wants to be registered on his child’s birth certificate as the “father” despite giving birth to the baby.

A senior High Court judge threw the claim out in September, citing the “basic facts of life” which make Mr McConnell the child’s mother regardless of his legal gender.

But Mr McConnell is now seeking to overturn the decision before Lord Burnett of Maldon, the head of judiciary, Lady Justice King and Lord Justice Singh.

If successful, his child would become the first in the UK to legally not have a mother.

Lawyers representing Mr McConnell argued that the Registrar General should modify the current birth certificate form to protect the rights of transgender people by offering the gender neutral options “parent one” and “parent two”.

“This is a claim brought by a man who has given birth to a child,” Hannah Markham QC, on behalf of Mr McConnell, told the court.

“In society, being a mother is a social construct and for a parent trying to move away from the terms [mother and father] because of their gender dysphoria, then that is an offence to their right to a private life, an offence to their being and identity.

“It’s not a minor inconvenience. It is not a trivial matter. It is significant.

“To misgender someone causes distress.”

Lord Chief Justice Maldon raised concerns about what the “legal consequences” could be to current legislation if the word “mother” is to be replaced on official documents.

“I don’t carry in my head the extent to which the words mother or father appear in primary legislation all over the place,” he said.

He added: “Where in all of this do we have evidence of the account of the interests of people in society who want to be named as the mother?”

Ms Markham stressed that the proposed change to official documents could be an option for parents, adding: “Choice can still exist.”

Opening her case, Ms Markham argued that society has moved on from the traditional term mother and that the law should keep up.

“We have to be a live, evolving law. We have to be in touch with society as society moves on,” she said.

Mr McConnell first started his legal challenge against the Government at the beginning of last year and his identity was initially protected by an anonymity Order.

But the High Court judge Sir Andrew McFarlane lifted it after a legal challenge was brought by a number of media groups including The Telegraph in light of a documentary Mr McConnell made showing his child’s face while arguing his family needed court anonymity to protect them from harm.

Mr McConnell was accused of being in "serious breach of his duty of candour to the Court" by failing to disclose the existence of a documentary called Seahorse, which he began filming three years ago.