Corporate CEOs and union chiefs would have to stand by political advertising they helped fund under legislation being introduced in Congress today.

The long-anticipated House and Senate bills come in response to a January Supreme Court ruling that opened the door to unlimited corporate and union spending on independent political ads. The bills' sponsors, including Sen. Charles Schumer, D-N.Y., and Rep. Chris Van Hollen, D-Md., say the ruling will allow corporate interests to flood the airwaves and determine the outcome of November's midterm elections.

President Obama said the legislation "will shine an unprecedented light on corporate spending in political campaigns" and urged Congress to act quickly to pass it.

"Powerful special interests and their lobbyists should not be able to drown out the voices of the American people," Obama said in a statement issued Thursday morning. "Yet they work ceaselessly toward that goal: They claim the protection of the Constitution in extending this power, and they exploit every loophole in the law to escape limits on their activities."

Senate Minority Leader Mitch McConnell, a leading opponent of campaign-finance restrictions, said the bill is about preserving an "election advantage" for Democrats.

"An effort to disregard the First Amendment and defy the Supreme Court in order to limit the speech of those who may disagree with you is an effort that has no place in this country," the Kentucky Republican said in a statement.

As we reported recently, the proposals center on new disclosure requirements. Donors to non-profit groups and trade associations, for instance, would be publicly disclosed if their money is used for "campaign-related" expenses. Their donations would remain confidential if the contributors bar the groups from using the money for political activity.

CEOs would have to appear on TV ads they helped bankroll and take responsibility for the ad's message. In addition, TV ads would list the top five donors who gave the largest amount of money available for campaign-related spending to the organization running the ad.

The bills also seek to limit the influence of foreign corporate interests in elections.

Sponsors hope to pass the legislation by July 4.

"If we don't act quickly to confront this ruling, we will have let the Supreme Court predetermine the outcome of next November's elections," Schumer said. "It won't be Republicans or Democrats; it will be corporate America and other special interests."

(Schumer's bill summary can be found here.)

The U.S. Chamber of Commerce and groups that favor fewer campaign restrictions, such as the Center for Competitive Politics, have blasted the proposals. In a statement, center officials said the bill attempts to "subvert" the high court's ruling and "intimidate dissenting groups into silence as midterm elections approach."

Updated at 7:30 p.m. ET: As the folks at The Center for Public Integrity note, the bills also include a provision that has been supported by some Republicans and groups that support fewer limits on campaign finance.

The proposed legislation also would ease some restrictions on when political parties can make expenditures on behalf of candidates. It would allow parties to spend unlimited amounts of their own funds in support of candidates and to coordinate that spending with the candidates, provided the candidates do not direct or control how the money is spent.

(Editor's Note: We've corrected this post. An earlier version erred when it said the proposal would affect the amount of money an individual could contribute to political parties. The proposed legislation leaves those limits untouched.)

(Posted by Fredreka Schouten)