Cllr King said: "Fortunately incidents of harassment towards councillors in the Harborough district are rare - but they do take place and this isn’t acceptable.
“Anyone, regardless of their background or political affiliation, should feel safe to become a councillor and be proud to represent their community.
“I have signed the public statement and have encouraged all councillors to do the same."
Cllr Knowles said: “Be it in council, on the streets, or in life in general I will never defend or agree with personal attacks, harassment of or encouraging others to indulge/participate in the harassing or personal attacks on others.
“Such practices are simply wrong on every level.“