WASHINGTON (CBSMiami/AP) – A new ad from President Barack Obama’s re-election campaign casts Mitt Romney as a greedy, job-killing corporate titan with little concern for the working class is just one facet of a new, multi-pronged effort to undermine one of the tent poles of his Republican rival’s candidacy: his business credentials.

The commercial will be coupled with a series of events Obama’s campaign is holding this week in Florida, Missouri, Iowa, Nevada and North Carolina to highlight Romney’s role at Bain Capital, a company he co-founded.

The new ad, which began airing Monday recounts through interviews with former workers the ultimate demise of a Kansas City, Mo. steel mill under Romney’s private equity firm.

“They made as much money off of it as they could. And they closed it down,” says Joe Soptic, a steelworker for 30 years. Jack Cobb, who also worked in the industry for three decades, adds: “It was like a vampire. They came in and sucked the life out of us.”

Romney, a multimillionaire, left Bain in 1999 to run the Salt Lake City Olympic Games but maintained a financial interest in the company after departing. He has said that his firm had a strong overall track record, creating jobs in prominent companies like Staples and Sports Authority, while acknowledging that some companies Bain invested in were unsuccessful.

The ad, at the unusual length of 2 minutes, will run in five battleground states: Iowa, Ohio, Pennsylvania, Virginia and Colorado. The campaign declined to describe the size of the ad buy though it’s in the middle of running a $25 million, month-long ad campaign in nine states. A longer version of the ad was being posted online Monday.

Romney campaign officials said they “welcome” any discussion about jobs. “Mitt Romney helped create more jobs in his private sector experience and more jobs as governor of Massachusetts than President Obama has for the entire nation,” Romney spokeswoman Andrea Saul said in a statement.

It’s unclear whether Obama, himself, will criticize his Republican rival on the subject when the president appears at events in New York on Monday or whether he’ll leave the skewering to campaign surrogates as he prepares to meet with foreign leaders during the G-8 and NATO summits later this week.

Also this week, Vice President Joe Biden holds two days of events in Ohio, where he’s expected to discuss Romney’s role as a corporate buyout specialist.

Romney previously had accused Obama of attacking free enterprise and called the criticism of his business background an attempt by Democrats to distract voters from the president’s record.

Both candidates were entering a new week in the campaign seeking to shift the focus back to voters’ No. 1 issue, the economy, from social issues that dominated after the president announced his support for gay marriage.

The two campaigns contend that in a nation where unemployment is hovering around 8 percent, voters will choose between Obama and Romney based on economic arguments. Obama is trying to convince voters to stick with him as he heralds an economic rebound, as sluggish as it is. Romney counters that Obama has had enough time, and only he – with his deep background in business – knows how to jump start the nation’s job market.