Sen. Bernie Sanders Bernie SandersButtigieg stands in as Pence for Harris's debate practice Bernie Sanders warns of 'nightmare scenario' if Trump refuses election results Harris joins women's voter mobilization event also featuring Pelosi, Gloria Steinem, Jane Fonda MORE (I-Vt.) in an internal email warned his campaign surrogates against “bullying and harassment of any kind," according to the HuffPost.

In the email, which the news outlet obtained, Sanders also called on his supporters to "do our very best to engage respectfully with our Democratic opponents."

ADVERTISEMENT “As we engage with our opponents in the Democratic primary, we will forcefully present our views and defend ourselves against misrepresentations,” Sanders, who last week announced his candidacy for the 2020 Democratic presidential nomination, wrote. “But, let us do our very best to engage respectfully with our Democratic opponents ― talking about the issues we are fighting for, not about personalities or past grievances. I want to be clear that I condemn bullying and harassment of any kind and in any space," he added.

In his email on Saturday, Sanders reportedly said his surrogates "must never forget what this campaign is about and who our real opponents are."

"They are the most dangerous president in modern American history and the powerful special interests who back his agenda," he wrote, according to HuffPost.

"We won’t always agree with them, but I expect those who speak on behalf of my campaign to always engage respectfully," he added.