Colorado Republican U.S. Senate candidate Gino Campana blasted primary rival Joe O’Dea on Friday after the latter announced plans to seek a spot on the June primary ballot by petition, suggesting O’Dea is too liberal to win support from GOP delegates at the state assembly.

In turn, O’Dea, the owner of a Denver-based construction company, ripped Campana, a real estate developer and former Fort Collins city council member, as a “tax-and-spend” liberal and added that he intends to compete for every vote in the primary.

Campana and O’Dea are among seven Republicans vying for the nomination to face Democratic U.S. Sen. Michael Bennet, who is running for a third term in November.

Major-party candidates can make the ballot two ways in Colorado – via the caucus and assembly process or by gathering signatures from fellow party members, something candidates were able to start doing this week. Senate and other statewide candidates can expect to pay petition firms in the neighborhood of $500,000 to collect the required 12,000 signatures this year, political consultants say.

O’Dea is the only declared Bennet challenger who has pulled petitions, leaving the others to vie for support from delegates who will be chosen at a series of party meetings starting at precinct caucuses the first week of March.

Announcing O’Dea’s decision to petition on Thursday, a campaign spokesman took broad shots at “political insiders,” listing “city council members,” a category that recently included Campana.

Campana, who announced last week that he’s going through assembly to secure a berth in the primary, berated O’Dea in a statement sent to Colorado Politics Friday morning.

“Joe Odea is petitioning onto the ballot because it’s painfully obvious he is way too liberal to win at the convention,” Campana said. “Joe claims everything he does is about ‘beating Michael Bennet,’ but you can’t beat Bennet if you’ve already joined him. Not only did Joe donate and help Michael Bennet get elected to the Senate in the first place, he inexplicably supported Joe Biden’s $1.2 trillion liberal give away masquerading as an infrastructure bill. We need a candidate who’s truly different from Michael Bennett, not someone who is going to go to Washington and vote the same way. Joe Odea’s liberal record is clear; he knows it and Colorado Republicans know it.”

Campana added: “I have built a grassroots campaign supported by President Trump’s advisors, and I will use this energy to win at the convention.”

Colorado Politics was first to report that O’Dea, a first-time candidate, donated $500 to Bennet’s first Senate campaign in 2010, along with a smattering of similarly sized donations to other Democrats over the years, including then-Gov. John Hickenlooper and State Treasurer Cary Kennedy.

Campana and O’Dea traded verbal jabs in November after O’Dea was the only Republican in the Senate primary field to tell Colorado Politics that he would have voted in favor of the $1.2 trillion bipartisan infrastructure bill supported by Bennet and later signed by Biden.

In an emailed statement to Colorado Politics Friday afternoon, O’Dea campaign spokesman Quinn Evans fired back at Campana.

“Gino Campana’s signature accomplishment on the Fort Collins City Council was to provoke a citywide taxpayer revolt when he pushed a regressive and ridiculous tax on grocery bags. Gino can stick his dishonest insults in his very own tax-and-spend-liberal ear,” Evans said.

“Joe is endorsed by the largest association of cops in Colorado, Donald Trump’s campaign manager in Colorado, and respected fiscal conservatives like state Sens. Jerry Sonnenberg and Ray Scott,” he said. “Joe’s going to compete for every vote in every corner of the state – Republican insiders, Republican outsiders, and all the many Coloradans who are tired of Joe Biden and Michael Bennet’s failed leadership.”

The two CEOs will likely face off in person for the first time on Feb. 3 at a candidate forum sponsored by the Republican Women of Weld in Fort Lupton.

O’Dea, who announced last week that he’d tested positive for COVID-19 while preparing for scheduled back surgery, was been unable to attend a pair of Senate primary forums last week in Lakewood and Monument and won’t be able to make a debate sponsored by the Colorado GOP on Tuesday at Colorado Christian University, Evans said.

Petitions are due to the Secretary of State’s Office on March 15. The Republican state assembly is set for April 9 in Colorado Springs, and the primary election is June 28.