Democrats hit corporations in a new TV ad on Wednesday, accusing them of spending millions in "secret" money to help elect Republicans.

The Democratic National Committee (DNC) released its latest television ad hitting GOP-allied groups that are spending millions to help defeat Democrats, and help Republicans gain control of the House and, possibly, the Senate.

The new ad, "Secret Plan," which is running on national cable beginning as soon as Wednesday, keeps alive the onslaught by Democrats against outside groups like the U.S. Chamber of Commerce and American Crossroads, the group affiliated with former George W. Bush advisers Karl Rove and Ed Gillespie, that have spent on behalf of the GOP in the closing weeks of the campaign.

"You’ve seen the ads. Millions being spent by right-wing groups to buy an election," the DNC ad says. "All from secret donors. What’s not a secret is why: Republicans and their corporate buddies want to be back in charge."

Democrats have sought to make the attacks on the GOP-allied groups a part of their overarching message this fall, which is to warn that Republican victories on Nov. 2 would mean a return to policies that benefit corporate interests. 

Absent from the ad, though, was the accusation that Democratic leaders levied earlier this month that corporations were possibly accepting foreign money to fund their political efforts. The new ad focused instead on the general secrecy surrounding the groups' funding, due to the fact that they're not forced to disclose their donations.

"The debate over the secret money Republican-aligned groups are spending to win the election and the economy is inextricably linked," wrote DNC spokesman Hari Sevugan. "Because if Republicans win, they are going to reward this special interest backing by returning to the economic policies of the Bush era that cost eight million Americans their jobs."

Sevugan said that the new ad also shows how the issue of corporate spending in elections is "resonating with voters," despite the complaints from some Democrats that the focus on outside groups might be misguided.