A new Obama campaign TV ad in nine battleground states targets Mitt Romney's credibility as a job creator, claiming the former Massachusetts governor oversaw "one of the worst economic records in the country."

"When Mitt Romney was governor, Massachusetts lost 40,000 manufacturing jobs - a rate twice the national average - and fell to 47 th in job creation, fourth from the bottom," the narrator says.

"Instead of hiring workers from his own state, Romney outsources call center jobs to India.  He cut taxes for millionaires like himself, while raising them on the middle class - and left the state $2.6 billion deeper in debt."

The one-minute spot, titled "Heard it Before," doubles down on Democrats' theme and message of last week, arguing that Romney in 2002 made similar economic promises which were left unfulfilled as governor.

The new ad will air in Colorado, Florida, Iowa, North Carolina, New Hampshire, Nevada, Ohio, Pennsylvania and Virginia,  the campaign said.

Senior strategist David Axelrod said today that the buy was "in the range of about $10 million" - roughly 10 times the amount spent on a TV ad attacking Romney's record at Bain Capital which aired on one day last month.

"It's an important one, and we're going put some weight behind it," Axelrod said of the new spot.

The ad campaign, Obama's second largest of the election cycle, is still less than half the $25 million he spent last month on a flight of positive ads, promoting Obama's record in the same nine battleground states.

In tandem with the ad, the campaign plans a barrage of events in the battleground states, starting in Iowa and Ohio today, featuring Massachusetts state officials who will discuss their views of Romney's record as governor.

Romney campaign spokeswoman Andrea Saul said the ad underscores a shift toward negative attacks from how Obama ran for office four years ago.

"Having abandoned 'Hope and Change,' the Obama campaign only 'Hopes To Change The Subject' from an abysmal jobs report," she said in a statement. "We're happy to compare the 4.7 percent unemployment rate Mitt Romney achieved in Massachusetts to President Obama's weak record any day."

This post has been updated.