Rep. Chris Van Hollen filed a lawsuit in federal district court Thursday against the Federal Election Commission, questioning its implementation of disclosures rules for nonprofits that run political advertisements.

But unlike most lawsuits against the FEC, the Maryland Democrat is trying to get the agency to be more stringent and require organizations to name the donors behind their commercials. Currently, the FEC’s rules do not require non-profit groups and other organizations to disclose contributors funding independent expenditures for federal elections.

“The disclosure of campaign-donor information is essential to our democracy,” Van Hollen said in statement announcing the suit. “However, we have found that the requirements in existing law have been significantly loosened by the FEC’s interpretation.”

Van Hollen’s lawsuit is the latest in the Democratic-led effort to answer the Supreme Court’s landmark 2010 Citizens United ruling, which held that corporations and nonprofits could use unlimited money from their treasuries to fund electioneering communications. Democrats introduced the DISCLOSE Act last Congress as a way of trying to force interest groups to reveal their donors’ identities, but the measure was never able to get out of the Senate.

Van Hollen’s move also comes as the White House is drafting an executive order that would require companies seeking government contracts to disclose donations to politicians and advocacy groups involved in election activities.

During the 2010 midterms, the three groups that spent the most on electioneering communications and did not disclose their donors were all nonprofits that ran ads opposing Democrats. These organizations consisted of the U.S. Chamber of Commerce, which spent $32.9 million on such ads, the American Action Network with $20.4 million and Americans for Job Security with $4.6 million.

In addition to the lawsuit, Van Hollen also filed a petition Thursday with the FEC asking the agency to have a new rulemaking process that would require organizations making independent expenditures to disclose the identity of their donors.

Several campaign finance reform groups applauded Van Hollen’s suit and FEC petition as efforts to bring more disclosure from these nonprofits and others, like American Crossroads.

“Improper FEC disclosure regulations are the principal reason that more than $135 million in contributions spent to influence the 2010 Congressional races were kept secret from the American people,” said Fred Wertheimer, president of Democracy 21. “The two actions taken today by Representative Van Hollen seek to ensure that nonprofit groups and others making campaign expenditures will not be able to keep the donors funding their activities hidden from citizens and voters in the future.”

But the lawyer who launched the Citizens United case said Van Hollen’s lawsuit was a partisan move with no case law to back it up.

“It has no merit,” said James Bopp Jr., who has won several major cases involving electioneering communications. “The Federal Election Campaign Act is limited to only regulating matters that relate to elections or for the purpose of influencing elections. And they want the disclosure of donors who have utterly nothing to do with elections.”

Bopp said he will consider submitting an amicus brief as the case progresses, but that the lawsuit is currently just a partisan ploy.

“I always assume when incumbent politicians try to use campaign finance laws, that they are seeking to do it for their benefit,” he said, bringing up the fact that Van Hollen is a two-term former Democratic Congressional Campaign Committee chairman.