The California Medical Association has sent a letter warning a California Chiropractic Association official who they say encouraged opponents of a mandatory vaccination bill to stalk lobbyists advocating for the legislation.

The emotional debate over Senate Bill 277, which would make vaccinations compulsory for California schoolchildren and passed the Senate last week, has taken a personal turn in recent weeks. Lobbyists championing the bill on behalf of the California Medical Association and the California Academy of Family Physicians have attracted the attention of bill opponents, who have begun sharing information on the lobbyists and disseminating photos of their locations on social media.

California Chiropractic Association President Brian Stenzler has spurred them on, according to a letter signed by California Medical Association CEO Dustin Corcoran, with a video in which Stenzler tells an SB 277 opponent who asks about the two lobbyists to follow them “all day long – follow them to a T.”

“Your video instructing people to stalk the lobbyists has the potential to turn an already volatile situation into an explosive one with very grave consequences,” the CMA’s letter to Stenzler says, directing him to halt “all activities that could incite, lead to, or result in harm to CMA employees or others involved in the SB 277 debate and to send a strong message to your members and your constituents to do the same.” The letter from the doctors group warns it will take “all necessary action to protect our employees and representatives.”

In a police report filed last week, the CMA depicted a hostile climate with the potential for violence, echoing reports of lawmakers receiving threats from bill critics. Following of “a number of online threats and threatening activity aimed at our employees” and “a consistent pattern of irresponsible rhetoric that results in statements threatening harm, or encouraging harassment or stalking of our employees,” the report says, the medical group has begun locking their doors during SB 277 hearings and having staff travel in pairs.

Parents who have flooded Sacramento to decry SB 277 have found an ally in the California Chiropractic Association. The organization’s officials have denounced the bill at hearings and legislative rallies. Donations to a leading anti-SB 277 group flow to a media fund managed by the chiropractors organization.

The California Chiropractic Association has made statements against overly aggressive behavior, warning in an April press release that the organization “strongly condemns inappropriate actions, personal attacks or threats of any kind.” A spokesman for the organization was not available for further comment on Tuesday.