The EU's top court Tuesday ruled that Bulgaria must issue an identity document or passport to the stateless baby of a same-sex couple from Bulgaria and Gibraltar.

The case concerns a girl who was born in 2019 in Spain where she was given a birth certificate that lists her two mothers as parents. But she could not receive Spanish citizenship as neither of the women is Spanish.

The Gibraltarian mother also could not pass on her British citizenship to the baby as she was not born in Britain or Gibraltar.

Bulgarian citizenship remained the only option which would allow the baby to travel. But since Bulgaria does not allow same-sex marriage and does not recognise same-sex marriages conducted abroad, the authorities refused a request for citizenship.

They insist that for a Bulgarian identity card or passport, the baby needs a Bulgarian birth certificate, which cannot include two people of the same sex and should only list her biological mother.

The two women have declined to reveal which one of them gave birth to the girl. 

The Bulgarian mother took the case to Sofia's Administrative Court, which decided earlier this year to consult the European Court of Justice on the issue.

"The Member State of which the child is a national is obliged to issue an identity card or a passport to that child without requiring a birth certificate to be drawn up beforehand by its national authorities," the CJEU said in its ruling Tuesday.

The Sofia court will now have to issue its own decision in conformity with the CJEU's opinion, before which the baby cannot leave Spain. 

The two mothers and the Deyshtvie LGBTQ rights organisation, whose lawyers represented them pro bono in court, welcomed the decision on Tuesday as "a huge step for all LGBTQ families in Bulgaria and Europe".

They said they hoped it could help thousands of same-sex parents, whose children are at risk of citizenship limbo because of legislative differences across the EU member states.

The couple's lawyer Denitsa Lyubenova vowed to take the legal battle even further in order to enable the baby to become the legal heir of both women.