Political advertisements would have to clearly identify their top three funders under legislation that state Sens. Jerry Hill and Mark Leno introduced Thursday, Dec. 20.

The DISCLOSE Act, which stands for Democracy Is Strengthened by Casting Light On Spending in Elections, would also require campaign websites to identify the top funders of political ads.

An earlier version of the legislation cleared the state Assembly this year by a 50-26 vote but did not get through the Senate before the legislative session concluded. Hill, who had served in the Assembly last year, was elected in November to the Senate, where he now represents District 13, which includes most of San Mateo County and northern Santa Clara County.

"This legislation is vital to protecting the integrity of our democratic process and ensuring fair elections in our state," Hill, D-San Mateo, said in a statement. "After seeing billions of dollars flow into elections across our country after the Citizens United decision, we need the DISCLOSE Act now more than ever."

The legislation, Senate Bill 52, is sponsored by the California Clean Money Campaign and it would apply to advertising for ballot-measure campaigns, independent expenditures and issue advocacy, according to the announcement from the Leno and Hill. Trent Lange, the organization's president, said his group is "thrilled" by the legislators' effort to push through what he called a "crucial transparency legislation."

"Over 350 organizations and leaders endorsed the last version, and 84,000 Californians signed petitions for it, demonstrating the rising outcry to stop Big Money special interests from deceiving voters when they fund political ads," Lange said in a statement.

Leno, D-San Francisco, pointed to the "large sums of money" contributed by unnamed organizations in the most recent election as a reason for the act.

"The only way to stop this covert financing of campaigns is to require the simple and clear disclosure of the top three funders of political ads so voters can make well-informed decisions at the ballot box," Leno said in the statement.

According to Lange, the legislation would replace the fine-print disclosures that are currently required with full-screen listings of the top three funders and links to committee websites for more information. The bill would also ensure that the listed funders are actual individual, corporate or union contributors, not "sham nonprofits or misleading committee names."