The sponsor of some academies accused of returning to the notorious Section 28 legislation has denied the claims, saying it “abhors” discrimination.

The United Learning Trust, which sponsors schools including Accrington Academy, was one of those accused by the British Humanist Association of either replicating Section 28, or of being “overly vague” on the issue.

On Monday, the BHA said it had identified at least 45 schools that either had replicated language banning the “promotion” of homosexuality in the classroom or were “unhelpfully vague on the issue.”

The trust has said that the row came after a misunderstanding over policy wording, and that it “abhorred” discrimination.

Academies run by the United Learning had told parents: “Staff are able to engage in objective discussions on homosexuality but not to promote it.”

A spokesman for United Learning said: “We abhor discrimination of any kind and are proud of our track record both as an employer and educator in dealing with issues surrounding diversity.

“We have amended our sex and relationship policy to remove any unintended interpretation and look forward to continuing our work to highlight this important issue”.

Introduced in 1988 under Margaret Thatcher’s Government, Section 28 of the Local Government Act banned the “promotion” of homosexuality by local authorities and said that schools “could not promote of the acceptability of homosexuality as a pretended family relationship”.

Section 28 was repealed in England and Wales in 2003 and in Scotland in 2000.

Over the weekend it was revealed a Change.org petition had been set up by LGBT campaigners against three schools: Castle View Enterprise Academy in Sunderland (CVEA), Swindon Academy and Stockport Academy.