Rep. Doug Lamborn is making his final stand Monday to keep his name on the ballot this November after the Colorado Supreme Court removed it last week over a technicality.

Lamborn, who has represented Colorado’s 5th District for more than 11 years, will appear in federal court Monday after filing a lawsuit against the Colorado secretary of state claiming that the rule that caused officials to boot him from the ballot is unconstitutional.

Lamborn is set to appear in court at 9 a.m. local time at the Alfred A. Arraj United States Courthouse in Denver.

The state supreme court threw out 841 of the 1,783 signatures two contractors had collected for Lamborn because the signature-gatherers were not Colorado residents, a state law requirement.

That left Lamborn with 942 signatures on his petition to file for re-election.

Candidates in Colorado need 1,000 to be on the ballot.

Lamborn’s campaign appealed to the U.S. District Court of Colorado, saying the residency is a violation of free speech and free association, the Denver Post reported.

“We believe that the part of Colorado law that requires petition gatherers to be residents of the state is manifestly unconstitutional, and controlling case decisions here in Colorado and courts around the country have agreed with that assessment,” Lamborn’s spokesman Dan Bayens said in a statement.

The 5th District will likely remain in Republican hands regardless of whether Lamborn is the party’s nominee.

President Donald Trump carried the district by 24 points in 2016, and Inside Elections with Nathan L. Gonzales rates the race Solid Republican.

Lamborn had nearly $585,000 cash on hand at the end of the first filing quarter of 2018, per Federal Elections Commission data.

GOP State Sen. Owen Hill, who was party to the state court lawsuit that kicked Lamborn off the ballot, had $218,000 cash on hand, while El Paso County Commissioner Darryl Glenn had $160,000.