WASHINGTON (AFP) ― The U.S. presidential race grew increasingly hostile and bitter Saturday with President Barack Obama releasing an attack ad that blamed Republican rival Mitt Romney for shipping American jobs abroad.

Obama, who with a stubborn unemployment rate of 8.2 percent, is fighting historic precedent to keep his job, poured scorn on his White House opponent’s business record, intensifying his recent character assassination of Romney.

The 32-second ad alleged that Romney, when head of venture capital outfit Bain Capital, had links to companies that chose to lay off U.S.-based workers and move those jobs to plants in Mexico and China instead.

The commercial, titled “Firms,” aired just days after the Obama campaign seized on government records that suggested Romney remained in charge at Bain for three years beyond February 1999, when he officially stepped down.

The date is considered crucial as after that year Bain is said to have invested in companies that moved jobs abroad. Romney has denied having any managerial influence at the Boston-based investment firm beyond 1999.

With an off-tone Romney rendition of the patriotic anthem “America the Beautiful” ringing in the background, the ad, which aired in nine states as well as on YouTube, also accused the Republican contender of outsourcing jobs to India when he was governor of Massachusetts between 2003 and 2007.

Romney said on Friday that the Obama camp’s claims about his involvement in moving jobs abroad were “false, misleading” and “wrong-headed,” but the Democrats insist the charges are valid.

In a third salvo, the officially approved campaign ad hit out at the Republican candidate for having “millions in a Swiss bank account,” and of shoring up money in tax havens such as Bermuda and the Cayman Islands.

“Mitt Romney’s not the solution. He’s the problem,” concluded the ad.

Romney amassed much of his estimated $250 million fortune at Bain and he has said he is proud of the work he did there, but he has released only one past tax return and has refused to bow to demands from Obama to release more.

The issue of jobs is considered crucial as no U.S. leader since World War II has won a second term while unemployment was above six percent, other than Ronald Reagan, who was reelected despite a 7.2 percent jobless rate in 1984.

In an already heated campaign, Obama has sought to paint himself as a down-to-earth American ― in contrast to his portrayal of Romney as an “out of touch” corporate raider who cares more about profits than everyday people.

Obama, on a tour of the battleground state of Virginia ― which he won in 2008 and is narrowly leading at present ― continued to batter Romney’s record in a speech in Glen Allen on Saturday.

“You know, when the American auto industry was about to go under and my opponent was saying, ‘let’s let Detroit go bankrupt,’ I made a bet on American workers ... and right now GM is number one again,” Obama said.

“Mr. Romney has a different idea. He invested in companies that have been called pioneers of outsourcing. I don’t want a pioneer in outsourcing. I want some in sourcing. I want to bring companies back.”

The president’s pitch however ran into Romney supporters at a campaign event in Clifton, Virginia, where they held up signs that read “Hope isn’t hiring,” in a biting reference to Obama’s “Hope,” poster from the 2008 campaign.

Romney has played up his experience in the private sector, arguing that with the United States caught in a sluggish economic recovery he is best equipped to deliver policies that can put more Americans back to work.

But Democrats have rounded on his career at Bain, exemplified by a much used black and white photograph of Romney and fellow executives stuffing their pockets and mouths with dollars, to raise doubt over his credentials.

Obama’s spokesman Jay Carney said the attack ad was legitimate because Romney was citing his time at Bain “as his top qualification for being president.”

On Friday, Romney used television interviews to defend his record, stating he had “no role whatsoever in the management of Bain Capital after 1999,” and said Obama “ought to say that he’s sorry,” for the attacks on his reputation.