The U.S. Chamber of Commerce is up with its first television ads of the 2012 campaign, praising three Republican congressmen and one GOP senator and slamming two Democratic senators for their policies.

The Chambers ads slam Sens. Sherrod Brown (Ohio) and Jon Tester (Mont.), two potentially vulnerable Democrats who have voted with their party on economic issues. Another ad praises Sen. Dean Heller (R-Nev.), who is locked in a tough election battle with Rep. Shelley Berkley (D-Nev.).

The group did not say how much money is behind the push, but said the ads will run on broadcast and cable television in 15 markets.

The Chamber is also running ads for Republican Reps. Dave Reichert (Wash.), Pat Meehan (Pa.) and Tom Latham (Iowa). Because of redistricting, Latham is facing off against fellow incumbent Rep. Leonard Boswell (D-Iowa), while Meehan represents Philadelphias Democratic-leaning suburbs and could face a tough reelection battle. Reichert has survived a number of tough races and his district is likely to become much safer from redistricting.

While the Chamber never endorses in the presidential race, it made no bones about attacking President Obama in many of the ads in attempts to frame his signature economic policies — including Obamacare — as job-killers.

The Democratic Senatorial Campaign Committee pushed back against the ads, pointing out that Heller, Brown and Rehberg voted against increasing the debt ceiling, which the Chamber supported.

"Republicans like Dennis Rehberg, Dean Heller, and Josh Mandel know exactly how the DC game is played.  You can tell the Chamber to take a long walk off a short pier and they will still come crawling back," said Matt Canter, spokesman for the Democratic Senatorial Campaign Committee.

Click here to watch the ads.

Updated at 3:20 p.m.