Sidecar warned its D.C. customers in an email today that regulations proposed by the D.C. Taxicab Commission could force the service to “shut down” in the city, a move the city agency called a “PR stunt.”

“The DC Taxicab Commission (DCTC) doesn’t want Sidecar in Washington, D.C. and has proposed regulations that will force Sidecar to leave the Nation’s Capital,” the company wrote in an email with the subject line “Don’t Let the DCTC Shut Down Sidecar.” ” We need your help to prevent these regulations from taking effect and to keep Sidecar in DC. Take action now!”

A proposed set of regulations would provide a framework to license and regulate “private sedan service,” like uberX and Lyft, which would be “distinguished from the non-profit activity called ‘ridesharing,’ which is not within the Commission’s jurisdiction to license or regulate.” The DCTC says these regulations will “address the unique issues raised by private sedan service, including rules to require adequate insurance, to ensure the safety of passengers, drivers, and the general public, to protect consumers, and to require payment to the District of a passenger surcharge, and for other lawful purposes within the authority of the Commission.” This could include background checks and limiting a driver’s hours. A hearing will be held April 30.

The Sidecar email sent to customers claims the “rules are not designed to promote safety or access; they are designed to curb competition and limit consumer choice.” Numbers, email addresses and Twitter accounts for the DCTC, Councilmember Mary Cheh (who chairs the transportation committee) and Mayor Vincent Gray are provided in the email.

When asked specifically how the regulations would drive Sidecar out of town, a spokesperson said in an email that the “proposed shifts would preclude casual drivers from participating on the platform (for example, commuting to and from work). Additionally, these regulations prohibit the use of destination. With Sidecar, riders enter their destination when they request a ride and a driver chooses to accept the rides that makes sense for them.”

The DCTC strongly pushed back against Sidecar’s claims, calling the email a “PR stunt.”

“The proposed rulemaking is not intended to shut anyone down,” DCTC Chairman Ron Linton said in an email. “This PR stunt is an attempt to play on the public’s emotions who are not aware of the details. A public hearing is scheduled for April 30 and written comments can also be submitted; all with the objective to get feedback and provide a forum to explain what specifically may be harmful and offer contributions for rules to protect consumers’ interests.

“Contrary to their statement the proposed rules do not preclude the casual driver from participating, rather the proposed rules support the ability of a vehicle owner to provide commuting transportation. There is nothing that prohibits the use of destination and as matter of fact it’s unclear what ‘prohibit use of destination’ even means. This nonsense is typical of those who do not want to participate in the community structure and just do what they want.”

A fan of the proposed regulations? Cab drivers. Or at least the Teamster union representing them. “As D.C. taxi drivers know, these ‘private sedan services’ have been operating illegally in D.C. for quite some time,” the Teamsters said in a release. “We are continuing to request that the commission take aggressive action against them until a level playing field is established. It’s not fair that they are allowed to operate in our city without even the most basic of regulations. We do applaud the commission for finally taking this first step.”