The education secretary, Gavin Williamson, has stressed the need for teachers to be politically neutral in the classroom, following the publication of controversial new guidance warning schools not to use resources produced by organisations with “extreme political stances”. Interviewed by his old politics teacher at the virtual Conservative party conference on Monday, Williamson said comparatively little about the impact of the coronavirus pandemic on schools and universities, where there have been multiple outbreaks and tens of thousands of staff and students are self-isolating. Instead he warned teachers in England of the need for political impartiality in schools and urged them not to influence their students inappropriately. “Political impartiality in our education system is an incredibly important principle to uphold,” he said in response to a question posed by a party member. “It’s not just a matter of opinion, it’s also a matter of law. It’s important we give pupils the context in order for them to be able to learn and form their own opinions. They should not be influenced in an improper way.” Williamson’s comments followed the publication last month of guidance for school leaders involved in setting the relationships, sex and health education (RSHE) curriculum, which categorised anti-capitalism as an “extreme political stance” and equated it with opposition to freedom of speech, antisemitism and endorsement of illegal activity. The guidance said: “Schools should not under any circumstances use resources produced by organisations that take extreme political stances on matters. This is the case even if the material itself is not extreme, as the use of it could imply endorsement or support of the organisation.” Unions reacted with dismay to the education secretary’s conference appearance. Geoff Barton, the general secretary of the Association of School and College Leaders, said Williamson’s comments were aimed at appealing to the party faithful, rather than focusing on the immediate priorities of keeping schools and colleges open in the face of spiralling Covid infection rates in the community, and clarifying the arrangements for next year’s GCSE and A-level exams. Barton said: “Teachers are obviously aware of the importance of political neutrality in the classroom and don’t need a reminder from the education secretary … The government really does need to deal with the task at hand rather than playing to the gallery.” The schools minister, Nick Gibb, was due to meet union leaders on Monday to discuss plans for next year’s GCSEs and A-levels, which could include a three-week delay to allow for more teaching time. Mary Bousted, the joint general secretary of the National Education Union, said: “The RHSE guidance is dog-whistle politics and in issuing it Gavin Williamson has thrown a bone to the right of his party. We, however, are not going to be distracted from holding this government to account for their lack of competence.” Quizzed by Peter Ashton, his government and politics teacher at Scarborough sixth-form college, Williamson also reiterated the government’s intention to “throw away” Tony Blair’s target to get 50% of young people into university and focus anew on further education and technical and vocational qualifications. He also flagged the government’s intention to get more white working-class young men into higher education. They are the most under-represented group in universities. “That’s a shocking disgrace,” Williamson said. “It’s wrong. We are going to correct that.”