DENVER – Colorado businessman Robert Blaha, who invested $1 million of his own money for the chance to challenge Democratic U.S. Sen. Michael Bennet, and former Aurora city councilman Ryan Frazier failed to gather enough voter signatures to make the Republican primary ballot, the state’s top elections official said Thursday.

For the moment, two candidates out of an original 13 are in the June 28 primary: Fort Collins businessman Jack Graham and El Paso County Commissioner Darryl Glenn. Former state Rep. Jon Keyser, once seen as the GOP elite’s preferred candidate, has appealed a finding that he, too, didn’t get enough signatures.

Both Blaha and Frazier have five days to appeal the decision by Secretary of State Wayne Williams. A message left with the Blaha campaign was not immediately returned. Frazier’s campaign suggested it would appeal the ruling.

“We are fully committed to letting the process work itself out,” Frazier campaign spokesman Joel DiGrado said. “Our position is that we presented more than enough valid petitions and are fully prepared to win that argument in court.”