Just before a controversial genetically modified (GM or GMO) labeling bill came up for a cloture vote in the U.S. Senate on Wednesday, food and consumer advocates dropped over $2,000 on the chamber floor in a symbolic protest against what they are calling the "Deny Americans the Right to Know" (DARK) Act.

The action aimed to highlight the fact that senators who took money from biotechnology giants like Monsanto are voting against majority public opinion, as recent polls have found that roughly 90 percent of Americans want labels on GMO foods.

The legislation, a so-called "compromise" bill introduced in June by Sens. Pat Roberts (R-Kan.) and Debbie Stabenow (D-Mich.), would mandate GMO labeling nationwide but allow food companies to choose between using symbols, electronic codes, or packaging language—an unnecessary and confusing method, according to critics. The bill would also undo Vermont's landmark labeling law, which went into effect July 1.

Roberts and Stabenow are reportedly pulling out all the lobbying stops to get the bill passed in the days before the Senate breaks for the summer. According to Politico, that includes "letters being sent, staffs briefed, reports and FDA assessments flaunted, and farmers and consumers are being encouraged to inundate lawmakers with phone calls."

Politico notes that "The cloture vote is expected sometime after 3 p.m. If successful in winning the 60 votes needed, lawmakers can limit debate to 30 hours, setting up a floor vote as soon as Thursday." If they can't reach 60 votes, Sen. Bernie Sanders has vowed to put a hold on the bill.

"The American people have a right to know what they're eating," Sanders said during a press conference on Capitol Hill on Wednesday. "The timing of this legislation is not an accident. Its goal is to overturn and rescind the very significant legislation passed in the state of Vermont. I will do everything that I can to see that it’s defeated."

Activists say the legislation was negotiated behind closed doors with executives from Monsanto as well as other corporate organic companies, including Whole Foods, Stonyfield, and Smucker's. Lobbyists from the Organic Trade Association were also involved.

"This bill was written and approved by Monsanto and America's most corrupt food companies in a last ditch effort to avoid common sense, mandatory labeling of GMOs, while keeping the doors wide open for a flood of campaign cash," Dave Murphy, executive director of Food Democracy Now!, said Wednesday.

Murphy's group, along with other advocacy organizations, also staged actions in New Hampshire this week targeting the state's Republican Sen. Kelly Ayotte and the Londonderry-based Stonyfield Yogurt's headquarters for their central roles in the lobbying blitz. The activists say Ayotte has taken more than $10,000 from Monsanto in campaign donations.

The Senate last week approved the bill 68-29 in a procedural vote. According to an analysis of OpenSecrets.org data by the Organic Consumers Association (OCA), senators who voted 'Yes' received more than twice as much in contributions from the agriculture lobby than those who voted 'No' ($867,518 for the supporters vs. $350,877 for opponents).

OCA political director Alexis Baden-Mayer, who participated in the money drop, said, "When Congress moves to crush the will of 9 out of 10 Americans because they need companies like Monsanto to fund their campaigns, you know our democracy is in real trouble."

"The corporate lobbyists are totally corrupt," Baden-Mayer said. "These companies have organic brands, but they also sell a lot of GMOs that they don't want to label."