The coalition of nearly 300 faith-based investors with over $100bn in invested capital, which goes under the name of the Interfaith Center on Corporate Responsibility (ICCR), has launched a web-based campaign against the planting of GM sugar beets from the April 2008 planting season.
The campaign, at www.DontPlantGMOBeets.org , claims that allowing GM sugar into the US food chain would affect thousands of the most widely consumed products in the US.
Among the companies being targeted by the campaigners are McDonald's, Campbell Soup, Kellogg, Kraft Foods, Sara Lee, PepsiCo and Hershey's.
The ICCR says it is concerned about sugar beets and other genetically modified crops because of "weak governmental review and oversight, and the lack of long-term, independent and peer-reviewed safety studies" - a concern more often seen among European consumers, who remain largely opposed to any GM crops.
Consumers visiting the site will be encouraged to print off a letter to send to the food companies concerned.
It reads: "As a consumer, I am writing to urge your company to publicly oppose the spring 2008 planting of genetically modified sugar beets in the United States .
"You have the power to tell agribusiness firms that you won't buy sugar made from genetically modified sugar beets.
You should know that I am among the more than 50 percent of Americans who avoid genetically modified foods if given a choice."
It ends: "I do not want to be 'forced' to eat genetically modified sugar either because it is sneaked into my food on an undisclosed basis or because it is added into virtually all food and beverages."
The new sugar beet strain, created by Monsanto, was approved by the US Department of Agriculture in March 2005, and is modified to be resistant to Monsanto's Roundup herbicide.
"If the sugar beets in question are planted, genetically modified sugar will enter the food supply in early 2009," said Leslie Lowe, director of the energy and environment program at ICCR.
"If the US companies at the focus of the new ICCR campaign use genetically modified sugar, their exports to the European Union will require documentation and testing, an additional cost and inconvenience.
"These companies face major potential backlashes if they do not act now to stop the use of genetically modified sugar from sugar beets.
Not only can these companies send a clear signal that they will not buy, but they have done this sort of thing before."
She explained that, under pressure from consumers, McDonald's has already pledged not to use genetically engineered potatoes for its French fries, while General Mills does not use genetically engineered wheat and brewer Anheuser-Busch does not use genetically engineered rice.
"Campbell's Soup Co does not use genetically engineered tomatoes even though the company helped to develop such a tomato.
Now, it is time for these companies and others to make it clear again that they are not going to try to sneak genetically modified sugar into the diets of Americans," said Lowe.
The increasing presence of GM crops in the US food chain has led to a growing 'resistance movement'.
Activists groups have filed a lawsuit in California calling for the USDA to review its approval of the GM sugar beet, while planting of Monsanto's alfalfa, also genetically modified to resist Roundup, has been delayed after a major campaign against the crop in 2006 calling for a federal environmental review.