A grammar school that has previously been criticised for inviting the right-wing controversialist Milo Yiannopoulos to speak has announced plans to create an “unsafe space” incorporating texts including Mein Kampf.

Sixth form pupils at the Simon Langton grammar school for boys in Canterbury will take part in a forum which is described as “an antidote to the poison of political correctness” and examine “the most beautifully disturbed and disturbing ideas, all of them presented without trigger warnings”.

The school’s headteacher, Matthew Baxter, said that the forum would not involve the study of Mein Kampf but simply incorporate it in “wider debate”. But the optional classes for 17- and 18-year-old pupils were criticised by some students, who were told about the plans on Monday.

The scheme’s name appears to be a play on the phrase “safe space” – a zone in which a person or category of people can feel confident that they will not be exposed to discrimination, criticism, harassment, or any other emotional or physical harm.

Two pupils said that the teacher in charge, Professor James S, had joked about LGBT groups by presenting the term with a string of random letters and numbers appended to it. The school has also scheduled lectures on the subjects “Women versus feminism” and “not all cultures are created equal”.

James S, director of humanities at the school – which is mixed in the sixth form – told pupils that the first session would be devoted to a controversial memo circulated by the fired Google employee James Damore that claimed that women were innately less capable as engineers. James S defended it as a “much-needed forum for debate”.

But Sarah Cundy, 18, said: “When [James S] was talking about doing this, he said we’ll look at the memo and highlight the pros and cons of his argument. To hear a teacher say there are any pros at all in the argument did make me feel pretty uncomfortable.

“I think female and minority students are going to face more issues. I think there will be a rise in sexism, which I would say is already an issue at the school – especially with it being an all-boys school except sixth form.”

Connie Kissock, also 18, agreed, saying: “As a female student, when I hear male teachers promoting anti-feminist ideas it makes me worry, particularly in an all-male environment. Especially among younger students, it can seem like a joke but end up being taken further.”

She explained that while she “definitely support[s] discussing a broad range of ideas in academic environments” she believes the speaker events organised by James S have “become an attack on what they see as leftist bias. We’ve had a speaker on women’s antifeminism, we’re going to have one on why all cultures aren’t equal, implying that non-Western cultures are inferior”.

Students said that a PowerPoint presentation given by James S. on Monday included “a joke at the expense of the LGBT community”. Alice Lefever, 18, explained: “LGBT was mentioned in the PowerPoint, followed by a string of letters and numbers, none of which were intended to give representation, but instead to mock.”

Last year, the school was criticised for inviting Yiannopoulos, a former pupil, to speak. The event, which was also organised by James S, was cancelled because of “the threat of demonstrations at the school by organised groups and members of the public”.

James S told the Guardian: “The Unsafe Space is a much-needed forum for debate about a host of issues seen from both sides of the ideological spectrum. We are not interested in fomenting xenophobia, racism or sexism. We are interested in evaluating arguments, not putting stilts under postures.”

The school librarian, Janeen Barker, said she helped him put together the PowerPoint presentation and said the LGBT acronym was a real one and not a joke. She said: “I wanted to be as inclusive as possible by trying to use an LGBT-friendly term. I found the acronym LGBTQQIP2SAA on the following websites, both of which I thought were respectful of the community, as am I.”

Headteacher Matthew Baxter said the course was designed to enable pupils preparing for university to discuss ideas outside of the conventional curriculum. He said: “These are topics which sixth form students routinely discuss in their own time and ones which they should be able to discuss with adults in a school which encourages ‘free speech’ in all the highest academic traditions of such a phrase.

“This does not mean that inappropriate language is permitted – as this is checked and modelled when students are much younger.”

• This article was amended on 14 February 2019 to remove some personal information.