The initial step is to promote a concept (it was called propaganda). There is no need of any decree from the authority but to have the authorizations of the authority to conduct a political campaign and to organize a local plebiscite.
The fact to engage oneself in a local campaign should force the authorities to analyze the "concept". The concept of coexistencialism is as revolutionary today as the communism of Marx and Hengel was revolutionary in the middle of the XIX century. As communism spread his propaganda in using a dangerous negative energy: the jealousy, the authority should analyze the concept to see if the campaign does not present any national danger. Communism was a national danger and so the conscious analyze of the authority is a first step.
The other approach is to turn a movie of political fiction.