Andy Byers, who leads Framwellgate School, Durham, has written to parents asking for help countering the “abhorrent and unpleasant views” of politicians, which he says are being “streamed into households daily”.
Accusing the high-profile figures of espousing “many things that we are teaching students to be wrong”, he fears their comments about minorities may even be driving the victimisation of BAME and LGBT communities.
Citing a number of incidents “where a student has not felt happy or respected”, one of which saw the police involved, Byers said he has been left “embarrassed and ashamed” at the conduct of his students.
He took aim at “racist” comments by Tory leadership frontrunner Johnson, as well as US president Trump for mocking a disabled journalist and boasting about sexual assault. He went on to criticise Corbyn’s chronic failure to deal with anti-Semitism in his party and Eurosceptics such as Farage for stoking up “hatred of immigrants to justify their Brexit ideals”.
Adding “this is a difficult letter to write”, Byers begged parents for help countering racist and bigoted views, imploring them “not to shy away from talking about this with your child”.
“It is an inescapable fact that students are exposed to some abhorrent and unpleasant views,” he said, adding that other school leaders had voiced similar concerns.
He added: “Our political leaders, perhaps the worst we have ever seen, espouse many of the things that we are teaching students to be wrong.
“President Trump publicly mocked a disabled journalist and admitted (boasted about) sexual violence against a woman; our possible next prime minister has made Islamophobic remarks about the burka and, according to the news, racist comments about the French.
“Jeremy Corbyn tolerates anti-Semitism by allowing those members and MPs who are anti-Semitic to remain within the party, and Nigel Farage, and a depressing number of politicians, have stoked up hatred of immigrants to justify their Brexit ideals.
“What terrible role models our young people have.”
He said that some parents did not tell children racism and bigotry are wrong, adding: “These views are streamed into households daily for all to see. Many parents take every opportunity to counter this hatred and teach their children about tolerance and respect.
“Sadly, there are some parents who share and agree with these views or leave them unchallenged. Their children hear no counter argument, other than at school.”
Johnson, who is the favourite to become the next Tory leader and UK prime minister, has faced accusations of Islamophobia for comparing burka-wearing Muslim women to “letterboxes” and “bank robbers”.
It also emerged recently that he called French people “turds” in part of a BBC interview which did not air.
Trump mocked a New York Times journalist with a disability during a campaign rally in 2015 and once said that when he meets women he felt able to “grab them by the pussy” because he was famous.
Corbyn, meanwhile, has repeatedly been criticised for failing to expel anti-Semites from his party.
Most recently, MP Chris Williamson, who was expelled from the party in February for saying the party had “given too much ground” over anti-Semitism, was readmitted last week only to be suspended again.
Farage, who previously led Ukip and now leads the Brexit Party, faced numerous accusations of signalling anti-Muslim feeling and racism during the 2016 referendum campaign.
Byers suggested such conduct was influencing students’ behaviour and that teachers were left picking up the pieces.
He wrote: “We try to teach our students that they need to use the right language. It is wrong to say ‘that’s gay that is’, even about an inanimate object or to laugh at someone’s appearance; you can’t call someone a ‘f***ing Jew’ or a ‘spastic’; you can’t refer to Muslims as ‘terrorists’.
“Most right-minded people are probably horrified by this paragraph but I would urge you not to shy away from talking about this with your child. Bullying is a terrible thing.”
Warning parents he would not hesitate to report students to police where he suspected a hate crime had been committed, Byers added: “If you are a parent who thinks I am overreacting or who finds the views or actions of Trump, Johnson, Corbyn or Farage in relation to minority groups acceptable, then I am concerned.
“I doubt I am able to change your views but I need you to know that these are being passed on to your children. At the very least, you need to tell them to do the right thing.
“You need them to know that there are consequences to their actions and that making comments about someone’s appearance, race, culture, gender, sexuality or disability is not acceptable.”
HuffPost UK has approached Boris Johnson, the Labour Party and the Brexit Party for comment.