Some young people and children may feel “isolated and hurt” after a move by the education minister to withdraw guidance on supporting transgender pupils in Northern Ireland schools, Sinn Féin’s John O’Dowd has said.

Teaching unions have called it a retrograde step and called for the minister to publish the legal advice behind the decision.

Education Minister Paul Givan said the guidance was produced in response to “the kind of activist campaigns that were being pursued by a minority” and that he did not believe it to be lawful.

O’Dowd, who is Stormont’s finance minister and a former education minister, said the issue needed handled with “great sensitivity”.

The minister said all politicians needed to “watch our language and measure our tone”.

The detailed guidance from the Education Authority was first published in 2019, but a recent Supreme Court ruling that a woman is defined by biological sex appears to have led to a review.

The ruling has implications for the provision of single-sex spaces like changing rooms and toilets.

Givan has been criticised by other political parties for moving ahead while the Northern Ireland Equality Commission seeks a declaration from the High Court to address “uncertainties” over how to apply the UK Supreme Court ruling.

O’Dowd was asked during questions in the assembly if his department was also planning to uphold the ruling and apply it to its services.

The minister replied: “I will await the outcome of the Equality Commission’s review and then I think it’s best the executive discusses these matters before any individual moves forward.

“Always remember that within these discussions there are young people and children, who I’ve no doubt as a result of yesterday’s announcement, may and do feel isolated and hurt.”

Speaking on BBC’s Good Morning Ulster programme, Justin McCamphill, NASUWT national official for Northern Ireland, said teaching unions were “calling on the minister to actually publish the legal advice he’s been given”.

He said other executive ministers “have not issued similar advice” and called on executive parties to “tell us what their understanding is of the legislation”.

He added: “The problem we have is there is legal uncertainty… if the minister believes the law is different here he needs to publish why.”

Mr McCamphill said the most affected by this decision were the “young people and their voice has been left out of the conversation so far”.

He said the guidance had opened up discussions on how to handle situations.

“It also talks about the wider context… where it can be handled in such a way that you can overcome the challenges because it’s not just a simple black or white,” he said.

“Withdrawing the whole document you are withdrawing that framework that will allow those conversations to take place.”

Northern Ireland’s commissioner for children and young people has expressed concern over the decision.

“All children deserve to feel safe, dignified, heard and respected,” Chris Quinn said.

“The Northern Ireland Executive’s Children and Young People’s Strategy for 2020-2030, that sits under the Department of Education, sets out an outcome that recognises transgender children and who are at risk of not having their fundamental rights respected.”

Mr Quinn said all schools had “obligations and must continue to uphold these to ensure all children are safe and their rights are upheld”.