A national campaign has led a dozen companies to announce they will not renew their membership in the American Legislative Exchange Council (ALEC). Wal-Mart, the giant retailer under fire for allegedly bribing Mexican officials, encountered another wave of vitriol when it was reported that the company also was a member of ALEC. (Edgard Garrido/Reuters)

One of the most polarizing fights over money in politics has been unfolding this spring at annual corporate meetings, where shareholders are mounting an intensifying effort to push companies to disclose the money they spend on lobbying and political campaigns.

The transparency push, playing out at shareholders meetings from coast to coast this spring, has received cheers from campaign finance reformers and some corporate governance experts. It has drawn ridicule from critics such as the U.S. Chamber of Commerce, who see the effort as an attempt by liberal groups to squelch the voice of the business world.

“This is all about intimidation,” Tom Donohue, longtime president of the Chamber, told reporters during a breakfast event Monday.

He noted that some proposals ask companies to stop spending on politics altogether.

“That’s the dumbest thing I have ever heard,” said Donohue, whose business-funded organization plans to spend a record $50 million on political campaigns this year.

For years, socially active shareholder groups — a universe that includes public pension funds, unions and religious environmental groups — have pushed companies to disclose details about their political spending. But the number of those proposals and support for them among established institutional investors have been on the rise.

The Sustainable Investments Institute, a Washington nonprofit that tracks shareholder resolutions, found that 109 — nearly a third of those up for votes at annual meetings in 2012 — sought more disclosures about spending on politics and lobbying.

The disclosure debate has taken on new urgency in an election year marked by anxiety over the economy and angst about the bigger role that wealthy individuals and special interests now play in political campaigns.

“We really have no idea how much is being spent and where it’s being spent,” said Nell Minow, a longtime corporate governance consultant who supports the push for transparency. “This is the defining issue of our time — the way that money and politics combine. If we don’t want the United States government to become a wholly owned subsidiary of corporate America, we need to do something about it.”

To date, 101 major companies have agreed to disclosure and board oversight of some of their political spending, according to Bruce Freed, president of the Center for Political Accountability, which rates companies on the issue. Freed and others argue that disclosure can help executives and directors avoid reputational risk to their firms.

In recent months, Coca-Cola, McDonald’s, Intuit and other firms have faced pressure after revelations that they had supported a business advocacy group that championed “stand your ground” gun legislation, which gained notoriety after the shooting of Florida teenager Trayvon Martin. A national campaign has led a dozen companies to announce they will not renew their membership in the American Legislative Exchange Council (ALEC). Wal-Mart, the giant retailer under fire for allegedly bribing Mexican officials, encountered another wave of vitriol when it was reported that the company also was a member of ALEC.

In 2010, Target became the subject of national protest because the retailer contributed to a business organization that backed a gubernatorial candidate with a record of anti-gay statements. The company, which portrays itself as gay friendly, instantly found itself at odds with an important customer base.

Disclosure advocates argue that such cases show the need for more transparency so that companies think carefully before backing certain causes or candidates. Some conservative and business groups say those cases represent bullying by the left.

“Those proposing these resolutions have policy views different from companies and want to use the disclosure as a whipping stick to force companies to stop engaging in the political and policy process,” said Andrew Pincus, a lawyer at Mayer Brown who has represented the Chamber and others opposed to the disclosure resolutions. “Government actions affect companies the way they affect all of us. It’s important for companies to participate in the political process. It’s a way of protecting shareholder value.”

At the heart of the ongoing fight over increased disclosure lies the growing world of third-party groups that are not required to disclose their donors. For years, such groups have given cover to liberals and conservatives, allowing them to fight battles over issues such as abortion rights and cutting taxes in virtual anonymity.

Lifting the veil on that secret spending could endanger their business model.

“Some of this is derived toward trying to defang very specific trade association groups,” said Jim Copland, director of the Center for Legal Policy at the Manhattan Institute, which tracks shareholder proposals and the groups behind them. “Academics, unions, nonprofits have tried to gin this up . . . to try to lower the influence of the trade associations themselves.”

Minow, the corporate governance advocate, said she would like nothing more than to defang those powerful organizations.

“It’s my hope to make groups like the Chamber and ALEC — as long as they continue to insist on obscuring what they are doing — so embarrassing to belong to that it’s no longer worthwhile for their members,” she said.

None of the shareholder provisions aimed at increased disclosure have succeeded this year, though some have received votes exceeding 35 percent, a high number compared with most shareholder resolutions. But passing the measures is not necessarily the point, advocates say. The main goal is to pressure companies to increase their disclosures, especially with the lack of action on Capitol Hill and within federal agencies.

“The ball has been tossed into the laps of shareholders and corporations,” said Trevor Potter, a former chairman of the Federal Election Commission who advised Sen. John McCain (R-Ariz.) on campaign finance and other issues during his presidential bid.

Last week, Potter helped lead a conference on disclosure issues that brought together business executives, corporate governance experts and activists for sessions with titles such as: “The battle over corporate political activity: Left wing plot, good governance, or both?”

In attendance was Dan Bross, Microsoft’s senior director of corporate citizenship, who has seen his company’s approach to political disclosure evolve.

In 2000, the software giant made payments to the Michigan Chamber of Commerce to run campaign ads, under the Chamber banner, helping one of Microsoft’s allies on Capitol Hill, then-Sen. Spencer Abraham (R). When it was revealed that Microsoft had paid $250,000 to help Abraham, the company and the candidate encountered stiff criticism.

Microsoft now discloses its political and lobbying expenditures on its Web site, including dues to trade associations and a breakdown of the political spending by those groups. Bross has emerged as a leader in efforts to encourage other firms to adopt more expansive disclosure practices.

“As a company, we believe in openness, transparency and accountability,” Bross said. “We are doing what we believe is right.”