OLYMPIA, Wash.—PepsiCo, Inc., Nestlé USA, Inc. and The Coca-Cola Company each have donated more than $1 million to defeat a Nov. 5 ballot initiative that would require labeling of genetically modified foods, the Grocery Manufacturer's Association (GMA) disclosed Oct. 18.

In total, businesses affiliated with the GMA have donated $7.2 million to defeat Initiative 522, according to a filing with the Washington Public Disclosure Commission.

Nevertheless, the same trend is under way in Washington, where corporations have spent more than $17 million in their efforts to defeat the measure. Once again, Monsanto and DuPont lead the way in spending; Monsanto alone has reportedly spent almost $5 million.

Even before the millions of dollars were spent to defeat GMO labeling in California and Washington, the food and agriculture biotechnology industry spent nearly $600 million in political contributions and lobbying "to ease the regulatory oversight of genetically modified foods," Food & Water Watch reported in 2011.

In response to such flagrant attempts to buy a vote outcome, several investor groups have joined in filing shareowner resolutions requesting that companies refrain from making political donations to influence elections. As You Sow has filed resolutions at Monsanto, DuPont, and Dow Chemical, and plans to file at General Mills and Abbott Laboratories as well. Green Century Capital Management says it will file a resolution with Kraft, and EWG will file at Coca-Cola and PepsiCo.

The investors say that they will contact almost 30 additional companies, and the top 50 corporate opponents to the California measure will receive letters requesting that they refrain from political spending.

"Companies that get involved in highly controversial public policy issues risk alienating their consumer base," Lucia von Reusner of Green Century said. "Using shareholder funds to publicly oppose transparency and the public's right to know threatens to erode consumer trust, and exposes the company to significant risks as a result."

"Smart companies increasingly recognize that the real cost of lost brand reputation and consumer loyalty far outweighs the imaginary costs of labeling," Faber of EWG added.