Two new independent expenditure ads began airing Tuesday in the hard-fought Colorado Senate race.

Freedom’s Watch, a conservative advocacy group, launched ads Tuesday in Colorado hitting the Democratic Senate nominee, Rep. Mark Udall, for missing a key vote last month on energy policy to attend a fundraiser back home.

The 30-second ad, with amusing graphics and whimsical music, shows gasoline prices rising as a narrator refers to the Congressman as “Skip Udall.”

Tim Pearson, deputy communications director for Freedom’s Watch, said the ad buy was “substantial,” though he declined to provide specifics. It is airing in the Denver, Colorado Springs and Grand Junction media markets.

Also Tuesday, the Democratic Senatorial Campaign Committee began airing an ad in the state that hits Udall’s opponent, former Rep. Bob Schaffer (R), for his ties to oil companies, noting that he voted for $10 billion in tax breaks for oil companies and earned $800,000 as an energy company executive after leaving Congress.

“Big Oil Bob Schaffer — do we really want him in the Senate?” a narrator concludes.

Udall and Schaffer are battling for the seat being vacated by retiring Sen. Wayne Allard (R).

Meanwhile, Freedom’s Watch recently received good news in its legal battle with libertarian activist Larry Klayman. A federal judge ruled last week that Klayman must pay the group more than $18,000 to cover costs associated with a copyright infringement case that Klayman lost last year.

Klayman had sued Freedom’s Watch, arguing that the group took the name that he had used for his legal work in the 1990’s, when he ran a Washington, D.C., watchdog group to sue President Bill Clinton and other public officials. Although Klayman had filed to register the name Freedom Watch with the U.S. Patent and Trademark Office in 2004, the federal agency, according to published reports, listed the group’s status as abandoned two years later.