The Daily Beast has learned from a source on the campaign of Kentucky Democratic Senate candidate Alison Grimes that they are “exploring all available legal options” to confront an anti-Grimes mailer sent out by the Republican Party of Kentucky and approved by the campaign of incumbent Republican Mitch McConnell labeled “Election Violation Notice.”

The official mailer, first reported by Salon.com and already derided by The Washington Post, is labeled on its envelope as containing facts related to a possible fraud being perpetrated on citizens across Kentucky.” It also includes the specific county that the voter lives in with the warning that “you are at risk of acting on fraudulent information that has been targeted for voters living in [county name].” The envelope also contains a warning about the federal penalties for obstructing the mail. Inside though, the message is anything but official.

The letter inside says that “information that has been red flagged as 100% false is being provided to you by Alison Lundergan Grimes.” It goes on to say that Grimes has launched an advertising campaign “filled with blatant lies intended solely to deceive Kentucky voters” as well as to attack the Democratic challenger for receiving campaign donations from anti-coal and anti-gun Hollywood celebrities. The letter cites The Washington Post’s Fact Checker blog calling Grimes’s ad “beyond the pale.”

Whatever the factual inaccuracies that the Grimes campaign is putting out, disguising the attack as “an Election Violation Notice” provoked outrage in a Grimes source, who described the mailer as “a despicable assault by Mitch McConnell on Kentucky voters.” Campaigns often exchange outrageous attacks but to do so in the guise of a government mailer is quite unusual. The McConnell campaign did not respond to a request for comment.

Update: The Grimes campaign announced early Friday evening that it is seeking an injunction “to prevent McConnell from engaging in these unprecedented and shameful campaign tactics.” The campaign also said that they would be asking state and federal authorities to investigate.