Republican Senate candidate Rep. Cory Gardner will start airing ads June 10 for the rest of June.
Three of the five Denver TV stations filed contracts with the Federal Communications Commission this week. The Gardner campaign will air 235 spots at a cost of $203,665.
Gardner is challenging Democratic incumbent Mark Udall, who has spent $468,260 on 706 spots during late April and May.
Outside groups also are airing ads for or against Gardner and Udall, with Republican and Democratic Senate campaign committees scheduling ads for September and October in preparation for the Nov. 4 election.