Want to keep up with the latest education news and opinion? Follow TES USA on Twitter and like TES USA on Facebook.

Donald Trump’s combative and controversial run for the US presidency is fuelling a spike in bullying among children at school, the country’s biggest union has warned.

Teachers have seen a steady rise in “harassing behaviour that mirrors his [Trump’s] words an actions on the campaign trail,” a statement from the National Education Association said.

“As educators, we teach our kids that kindness, collaboration and cooperation are important not just in school, but in in life,” said NEA President Lily Eskelsen García.

“Donald Trump sets an example that teaches the wrong lesson. He calls women fat pigs, wants to ban Muslims from coming to the country, refers to Mexicans as criminals, and makes fun of people with disabilities.

“The rise in vitriolic speech in classrooms and the anxiety this causes for some of our most vulnerable students shows that Trump’s rhetoric is far more damaging than previously imagined.”

The union - which has endorsed Hillary Clinton for president -cited a recent report by the Southern Poverty Law Centre, ‘The Trump Effect’, in which two-thirds of teachers surveyed said they had seen this impact.

On Monday, educators in a number of key states including Iowa, Florida, Michigan, New Hampshire and Pennsylvania participated in events to raise awareness of the issue. This will be followed by a digital marketing and direct mail campaign.

“Millions of children across our country are watching Donald Trump unapologetically belittle people who are different from him time after time,” Ellison said.

“He’s sending a disturbing message to our kids and it’s sinking in. Reports of bullying and harassment are on the rise in our schools, especially toward students of color, Muslim Americans and immigrants.”