Backers of a November ballot measure seeking to label genetically modified organisms are continuing to rake in contributions, in what could become the most expensive measure fight in Oregon history. Oregon GMO Right to Know, the campaign pushing the measure, has already collected more than $1.3 million in donations.

The checks it picked up this week include $40,000 from Berkeley-based organic pasta maker Annie's Homegrown, and $5,000 from Wisconsin cookie company Back to Nature Foods.

But that donation from Back to Nature Foods signals a larger mutation happening in GMO battles across the nation: Organic food companies are supporting GMO labeling against the wishes of their corporate investors.

Back to Nature Foods Company is partly owned by food giant Krafta fierce opponent of GMO labeling.

Bloomberg Businessweek examined this rift in a recent story on ice cream company Ben & Jerry's—and its parent company, Unilever. Ben & Jerry's has backed GMO labeling in Vermont, while Unilever has sued to block the state's new law.

The Businessweek story explains:

Ben & Jerry’s support of the law—a swirl of savvy public relations, financial backing, and grass-roots activism—pits the ice cream maker against the world’s biggest food companies, including its own corporate parent. Unilever has openly opposed state efforts to legislate GMO labeling, throwing money into campaigns to defeat an initiative in California. But it has quietly allowed Ben & Jerry’s to assert itself as a vocal proponent of such laws, especially in Vermont. “I don’t think they will ever want the potentially massive negative PR of trying to silence B&J,” says Andrew Wood, an analyst at Sanford C. Bernstein.If Unilever tries to play both sides of the issue, it may wind up hurting itself and Ben & Jerry’s. “In the short run, they might get away with ignoring what B&J is doing, but sooner or later it will catch up with them,” says Marion Nestle, a professor of nutrition and public health at New York University and the author of Food Politics, a book about how the food industry influences nutrition policy. Unilever’s stance makes it “look stupid,” Nestle says, and it could open up the company to boycotts from consumer activists angry about its hypocrisy. “I suspect we will be hearing much more about this.”

Businessweek profiled the biggest GMO labeling foe—Monsanto—earlier this summer. WW examined Oregon's upcoming ballot fight in April.