Monsanto is leading the fight to block a California ballot initiative that would require labeling of food with genetically modified ingredients.
Monsanto is the largest contributor so far. Pesticide manufacturer Dupont is close behind, with contributions totaling about $4 million. Other top contributors include PepsiCo, BASF, and Bayer.
In all, corporations opposing California’s GMO labeling initiative have contributed close to $25 million, while supporters have contributed less than $3 million.
Proponents of Proposition 37 say Californians have a right to know whether the foods they purchase were produced using genetic engineering, which they say often has unintended consequences.
In a blog post, Monsanto says supporters’ allegations that GM ingredients are untested and unsafe are not true.
The company, which sells genetically modified seeds for a wide range of crops, says special labeling for bioengineered foods would be misleading to consumers.
In the U.S., genetically modified corn, soybeans, and canola are staple ingredients in processed foods, from breakfast cereal to soup.
Follow Véronique LaCapra on Twitter: @KWMUScience