DENVER (AP) — Rep. Doug Lamborn is asking a federal judge to put him back on the Republican primary ballot.

The Colorado Supreme Court bounced the six-term congressman from the ballot earlier this month. The high court ruled that because some of the people who collected signatures for Lamborn didn't live in Colorado the signatures are invalid.

Lamborn sued last week. He argues the Colorado law requiring signature gatherers to live in the state is too narrow and violates the First Amendment.

If Lamborn is unsuccessful in his federal lawsuit, then his only option would be to run as a write-in candidate in the general election. He missed Colorado's Jan. 1 deadline for candidates to file as independents