Republican gubernatorial candidate Greg Abbott is questioning the legality of Democrat Wendy Davis’ upcoming book tour. Davis memoir, ‘Forgetting to be Afraid,’ goes on sale Tuesday. Davis has book signings scheduled across the state this week.

Abbott’s campaign manager Wayne Hamilton is requesting an opinion from the Texas Ethic Commission about campaign finance laws in connection to the tour. In a letter sent Monday morning, Hamilton raises several questions- including whether or not Davis’ publisher should be allowed to pay for the tour and other promotional events. Under Texas law, corporations are prohibited from contributing to political campaigns.

The letter reads, in part, “The goal of this advertising is nearly identical to the goal of advertising done by the candidate’s campaign; that is, to raise the candidate’s name identification, increase the public’s opinion of the candidate, and otherwise promote the candidate to the public.”

The Davis campaign maintains that the book tour is well within the law. “We were very careful to follow every legal guideline,” said spokesman Zac Petkanas.. “This frivolous stunt by the Abbott campaign is the clearest sign yet how worried they are about the power of Wendy’s story.”

Some advance copies of Davis’ memoir have already been released. The book reveals that Davis underwent two abortions for medical reasons during the 1990s. Davis launched into the national spotlight after her 13 hour filibuster to try to defeat stricter abortion laws in Texas, last legislative session. Davis said in an interview on ABC News Saturday that she did not bring up her own abortion story at the time because she did not want to overshadow the events of the day.