The SNP’s Stewart McDonald claimed that Ms McVey would bring back the infamous Section 28 legislation, which banned schools from teaching pupils about LGBT+ relationships. It was scrapped in 2003.

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Mr McDonald tweeted: “An Esther McVey premiership would almost certainly lead to the return of Section 28. This is her just laying the groundwork.”

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The former cabinet minister’s comments come amid a deepening row between Muslim parents and a Birmingham primary school over sex and relationship lessons.

Parents and other local residents have been holding almost daily protests outside Anderton Park primary school in opposition to its policy.

Nazir Afzal, a former chief prosecutor for northwest England, was brought in to run meditation talks between the local council, teachers and parents but announced on Thursday that discussions had broken down after six weeks.

He accused the government of acting “cowardly” for not being more specific about what young children should be taught, telling Sky News: “The government need to mandate what needs to happen around relationship education. What should be the curriculum, not just simply leave it for local interpretation because this is what will happen ... The government are cowardly in this regard.

“This is a political matter ... There are loads of people who still don’t believe in gay relationships, who still don’t believe in LGBT+ within the government party, within their coalition partners.

“And so they’re not prepared to get involved in this subject. And quite frankly unless the government do, we’re going to have this dispute rumbling on for years and years and years and it’ll get worse and worse and worse.”

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