Outside group hits Crist in new TV ad

[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2010/images/07/21/art.changingcharliead.youtube.jpg caption ="A new ad is out in Florida attacking Gov. Charlie Crist."] Washington (CNN) - An outside group is weighing on the Florida Senate race with a new TV ad attacking Gov. Charlie Crist for shifting his positions on taxes, the federal stimulus bill and cap and trade legislation.

The commercial is being funded by The American Action Network, a Republican think tank and advocacy group headed by former Minnesota Sen. Norm Coleman and Rob Collins, a former aide to House Minority Whip Eric Cantor. The commercial will run for one week in the Tampa/St. Petersburg and Panama City markets.

The ad accuses Crist, who in April left the GOP to run as an unaffiliated candidate in the Senate battle, of flip-flopping on an anti-tax pledge he signed when running for governor, as well running away from his support for the stimulus bill while still in the Republican primary.

The commercial also says Crist supports a job-killing "energy tax," the Republican code word for proposed cap-and-trade legislation.

"You can't trust Charlie Crist to fight for jobs - unless its his own job," a narrator warns in the 30-second spot.

The outside ad spending likely comes as welcome news to Republican candidate Marco Rubio, who trails Crist both in polling and money. Though Rubio had a blockbuster second quarter, raising $4.5 million, he spent most of it and finished June with $4.4 million in the bank to Crist's $8.2 million.

Crist and Rubio will face the winner of the Democratic Senate primary, either establishment-backed Rep. Kendrick Meek or self-funding billionaire investor Jeff Greene.