Following a week where the prime minister was accused of using"violent" language, the charity set up in honour of murdered Labour MP Mrs Cox said it had been working with the Committee on Standards in Public Life (CSPL) to develop a Joint Standard of Conduct to help protect election candidates.
The foundation said it will set out minimum standards of behaviour expected from all political party members, aiming to reach an agreement before the next election.
It added that intimidation was a "cross-party issues" which poses a threat to the “diversity, integrity, and vibrancy of representative democracy” in the UK.
Brendan Cox, Mrs Cox’s widow, said he was “shocked” by the type of language used in the Commons debate after Parliament was recalled on Wednesday.
He urged all sides to moderate their language, telling the Today programme on BBC Radio 4: “There is a willingness to jump out and decry the other side when they use language like ‘surrender’ or ‘traitor’ or ‘betrayal’.
“And I think that is inflammatory language, but I think as inflammatory are those people who have used the language of it being a ‘coup’ and a ‘dictatorship’. I think both of those approaches are unacceptable.”
The foundation added that it would actively promote and support the Nolan Principles of Public Life – selflessness, integrity, objectivity, accountability, openness, honesty and leadership.
It has been developed using recommendations made in the CSPL’s 2017 report on intimidation in public life and a review of existing internal party codes.
CSPL chairman Lord Evans said he was “delighted” by the progress in tackling intimidation, adding: “Standards in public life have rarely been more in the spotlight than they are today.”
Catherine Anderson, chief executive of The Jo Cox Foundation, said: “Jo’s murder in 2016 is a constant reminder to us that the threat of violence and intimidation towards MPs, candidates or anybody else in public life can never be acceptable.
“We all value vigorous political debate and freedom of speech but that should not extend to abusive behaviour designed to intimidate and silence people. It threatens our democracy itself.”