Six-term Republican congressman Doug Lamborn is in serious danger of not even being on the ballot this November after the Colorado Supreme Court ruled Monday that his name should not appear on the ballot in June for the GOP primary in his Colorado Springs district. At issue, as the Denver Post reports, is the 1,000 signatures needed to get Lamborn on the ballot.

Lamborn submitted 1,783 signatures to the Colorado Secretary of State’s Office, 1,269 of which were considered valid, which seems like a high proportion of faulty signatures, but it still appeared to be enough to kick-start the conservative congressman’s re-election campaign in Colorado’s 5th Congressional District. A lawsuit filed shortly after by five Republicans in the district raised new concerns however, calling into question the validity of signatures collected by two signature-gatherers hired by the campaign—apparently through a firm that specializes in signature collection—who were not, in fact, residents of the state, as required by Colorado law.

“The Denver District Court ruled that one of the gatherers was not a resident, and invalidated 58 signatures he collected. It found that the other—who had gathered more 269 signatures — was,” according to the Post. Even with the invalidated signatures, Lamborn still hurdled the 1,000 threshold with a couple hundred names to spare, “[b]ut the Colorado Supreme Court, which reviewed the case upon appeal, rejected the lower court’s ruling on the residency of the second gatherer, Ryan Tipple, which was based off the legal theory that he intended to move to the state,” the Post reports. That left the current member of the House Armed Services and Natural Resources committees with 942 signatures, 58 short of the 1,000 needed, leaving Lamborn off the ballot and out of the running for the GOP nomination for the seat he won by 32 points in 2016.

“Lamborn’s campaign said it planned to go to federal court to challenge the constitutionality of the Colorado law that the Supreme Court relied on in its Monday ruling,” the Associated Press reports. “It’s the third time a prominent Colorado politician has been stricken from the ballot this month due to the complexities of the state’s nominating system.”