Construction company owner Joe O’Dea has qualified for the Republican primary for the nomination to challenge Democratic U.S. Sen. Michael Bennet, election officials said Monday.

O’Dea is the first Republican to secure a spot on Colorado’s June 28 primary ballot for the seat. Seven other Republicans are vying to make the ballot at Saturday’s state assembly in Colorado Springs, where it will take support from at least 30% of the delegates to advance.

Of the 23,569 signatures submitted by O’Dea’s campaign, the Colorado Secretary of State’s Office said in a statement that 16,088 were valid – far more than the 12,000 required for U.S. Senate candidates, including at least 1,500 from each of the state’s eight congressional districts.

O’Dea came closest to the minimum requirement in the heavily Democratic, Denver-based 1st Congressional District, where he gathered 1,814 signatures. He had the biggest cushion with 2,478 signatures in the heavily Republican 4th Congressional District, which covers Douglas County and the Eastern Plains.

“We have the message, the team and the momentum to win this race,” O’Dea said in a statement. “Joe Biden’s puppet Senator, Michael Bennet, isn’t getting the job done. He has failed to stand up to the elitist fringe of his party and Coloradans are paying the price at the gas pump, on their heating bills, in the grocery store, and even when they try to buy their first home. This year, we will throw Michael Bennet’s retirement party. Let’s roll.”

The wealthy, first-time candidate – he put $500,000 into his campaign in the final quarter of 2021, according to the most recent available campaign finance reports – is the only Colorado Republican who circulated petitions in the U.S. Senate primary. Estimates pegged the cost of running a statewide petition drive at nearly $500,000, though candidates told Colorado Politics that the price had soared as the March 15 deadline approached to more than twice the per-signature price petition firms had initially quoted.

The other Republicans hoping to deny Bennet a third term are state Rep. Ron Hanks, real estate developer Gino Campana, Olympian and former GOP official Eli Bremer, nonprofit founder and former talk radio host Deborah Flora, former congressional nominee Peter Yu and political science professor Gregory Moore. An additional candidate, Pueblo business owner Daniel Hendricks, has participated in a couple of candidate forums but otherwise doesn’t appear to have mounted a campaign.

Bennet faces a long-shot challenge at Saturday’s virtual state Democratic assembly from first-time candidate Karen Breslin, an attorney and university instructor.