French schools are to replace the words “mother” and “father” with “parent 1” and “parent 2” under an amendment to a law passed this week.

Supporters of the change say it will stop discrimination against same sex parents but critics argue it “dehumanises” parenthood, is “ugly” and could lead to rows over who gets to be “parent 1”.

The amendment was passed by MPs on Tuesday night as part of a wider so-called law to build “a school of trust”, which among other things also makes attendance compulsory for all three-year-olds.

“This amendment aims to root in law children’s family diversity in administrative forms submitted in school,” said Valérie Petit, MP for the majority REM party of President Emmanuel Macron. Ms Petit, from the Nord department, said that the words mother and father, on all school documents such as pertaining to the canteen or authorising children to go on excursions, no longer took into account the recently-passed gay marriage law, nor the existence of same sex parents.

She added: “We have families who find themselves faced with tick boxes stuck in rather old-fashioned social and family models. For us, this article is a measurement of social equality.”