DENVER (AP) — A federal appeals court is rejecting what may be the final attempt to knock Rep. Doug Lamborn off the Republican primary ballot.

The 10th Circuit Court of Appeals in Denver on Wednesday dismissed an appeal by a group connected to one of Lamborn's primary challengers. The group had initially knocked Lamborn off the ballot with a lawsuit. They alleged Lamborn improperly used people from out of state to gather voters' signatures for his reelection bid.

But a federal judge reversed that ruling Tuesday and said Lamborn should be on the ballot. The appellate court refused Wednesday to overturn that decision, leaving Lamborn on the ballot.

Lamborn is a six-term congressman. He faces former State Senator Owen Hill, whose supporters brought the litigation, and other Republicans in the primary.