Republican congressional candidate Erik Aadland will try to win a spot on the June primary primary ballot at next month’s 7th Congressional District assembly after failing to qualify by petition, his campaign said.

Petitions submitted by Aadland, a former oil and gas executive and first-time candidate, fell short of the required 1,500 signatures from fellow Republicans, the Colorado Secretary of State’s Office told the candidate late Friday, prompting the move, an Aadland spokeswoman said.

The West Point graduate is one of five Republicans running in the Jefferson County-based district left open after this year’s election by Democratic U.S. Rep. Ed Perlmutter’s announcement in January that he isn’t seeking a ninth term.

“I have always been a grassroots candidate,” Aadland said in a statement. “This is my opportunity to seal my approval with the delegates and show that I am the candidate best equipped to win this congressional seat.”

Aadland jumped from the crowded U.S. Senate primary to the congressional race in December before Perlmutter’s announcement.

State Sen. Brittany Pettersen, D-Lakewood, is unopposed for the Democratic nomination to the seat, which has been pegged as a battleground race by national Democrats and Republicans.

Major party candidates in Colorado have two routes into the June 28 primary – gather enough petition signatures or win support from at least 30% of delegates to party assemblies. Candidates who take both routes simultaneously only need 10% support at assembly.

The GOP’s 7th CD assembly will take place in Colorado Springs on April 8, the day before party delegates meet to nominate statewide candidates at the state assembly.

The other Republicans running in the district are former legislative candidate Laurel Imer, economist Tim Reichert, attorney Brad Dempsey and Teller County activist Carl Anderson. Reichert and Anderson turned in their petitions last week, and Dempsey is gathering signatures.

Aadland announced on Feb. 22 that he was turning in petitions with “nearly 2,000 signatures,” but a review by election officials determined that he didn’t submit enough that were valid.

Once the secretary of state issues a statement of insufficiency – expected by end of day Monday – Aadland has five days to file a court challenge, which would amount to asking a judge to rule that some of the signatures that were ruled invalid should be counted. But the campaign doesn’t plan to take it to court, Aadland spokeswoman Christine Rourke told Colorado Politics on Monday.

“As a war veteran, I know what it is like to fight and win,” Aadland said. “After two tours in Iraq and Afghanistan, I learned to be prepared to adjust to the circumstances in front of me. I look forward to meeting with the delegates at the assembly and not only winning their vote, but their hearts as well.”

The campaign of one of his primary opponents threw some shade at Aadland in a statement welcoming him to the delegate chase.

“The Aadland Campaign just can’t decide what they want to do,” Imer’s campaign told Colorado Politics in a text message. “First a failed Senate run, second a failed petition campaign, and now they are trying in a last-ditch effort to go through assembly. On top of all of this, they are claiming to be a grassroots campaign after paying petition circulators and loaning his campaign well over $100k. That being said, we are looking forward to a competitive assembly and getting on the ballot on April 8.”

 Petitions are due at 5 p.m. Tuesday. The secretary of state’s office verifies petitions in the order they’re filed.