Rep. Cory Gardner, R-Colo., will go on the airwaves starting Tuesday, with a major television buy for his bid to unseat Democratic Sen. Mark Udall.  

In full, his TV reservations are worth $900,000, according to a Gardner campaign source. Of that sum, about $400,000 will be on broadcast, while $500,000 will be cable. The buy lasts from June 10 through the end of the month.  

The reservations include the Colorado Springs, Grand Junction and Denver television markets. The actual ad was not yet available. Gardner reported having $2.1 million in cash on hand at the end of the first quarter . The race is rated Leans Democratic by Rothenberg Political Report/Roll Call.  

Udall first went up on air at the end of April, putting $500,000 behind an ad attacking Gardner for his “history promoting harsh anti-abortion laws.” The spot focused on his past support for personhood — Gardner later said he no longer supported the legislation — and his support for a measure that would have prohibited abortion except to save the life of the mother.