Obama ad keeps pressure on Romney over offshore holdings

Since a report in Vanity Fair magazine last week that said Romney used offshore transactions and accounts to hold assets and possibly gain tax benefits, Democrats have leaned on the presumptive GOP nominee to release additional tax records.

Romney has released records from 2010 and an estimate of his taxes for 2011.

The new Obama ad opens with a title card reading, "Why would Mitt Romney invest millions in the Cayman Islands?" 

It is followed by video footage of conservatives, including Sen. Chuck Grassley (R-Iowa) and former Gov. Mike Huckabee (R-Ark.), questioning the use of offshore accounts.

The ad then reads, "There's one way to clear up the questions." 

It is followed by a clip of former Republican National Committee Chairman Michael Steele in an interview urging the Romney campaign to release more tax records to address any voter questions. 

The ad closes with a clip of Romney during a GOP debate, being asked when he will release his tax returns. "Time will tell," says Romney in the heavily edited clip.

Democrats have hit Romney on his work at private equity firm Bain Capital and on his wealth, hoping to paint him as out-of-touch with middle-class voters. 

President Obama jumped into the fray in an interview with a local New Hampshire television station on Monday, saying that Romney's finances need to be an "open book" for voters.

The Romney campaign, though, has hit back, accusing Obama of seeking to distract voters from the weak economy.