A tortious interference lawsuit allows you to sue the noncontracting person and recover damages for intentional or negligent acts that caused economic harm. A key element of intentional interference with contractual relations is that the defendant intended to disrupt an established business relationship.This blog talks about the Cal jury instructions and what a Plaintiff has to prove to meet their "burden of proof" in a civil case. Both California contract law and tort law allow for legal action when a third party wrongfully interferes with a contract or ongoing business relationship. A cause of action exists for negligent interference with another's prospective business advantage if the defendant acts unreasonably and wrongfully. If a third party unfairly interferes with a business contract or relationship and causes damage, a tortious interference claim may be a viable option. What this means is that they must have known about the contractual relationship and caused the breach anyway. Intentional interference with prospective economic advantage, and intentional interference with existing contractual relations Dkt. THE UNITED STATES IN THE FIELD (Government Printing Office, 1898). It is unlawful for any person to engage in picketing before or about a residential dwelling of any individual in the City of San José.