Actress and lifestyle guru Gwyneth Paltrow took to Capitol Hill Wednesday to join lawmakers in pushing for the mandatory labeling of foods containing genetically modified organisms (GMOs).

Paltrow was joined by her mother, actress Blythe Danner, and Democrat Senators Barbra Boxer (CA), Patrick Leahy (VT), Richard Blumenthal (CT), and Jon Tester (MT), who held a press conference in Washington to urge the Senate and President Obama to strike down the House-approved Safe and Accurate Food Labeling Act of 2015 (H.R. 1599), which would override state laws requiring GMO labeling.

“I’m not here as an expert,” Paltrow said from the podium. “I’m here as a mother, an American mother, that honestly believes I have the right to know what’s in the food I feed my family.”

Paltrow and other opponents of the legislation have labeled H.R. 1599 DARK, or the “Denying Americans the Right to Know” Act. The actress is seeking support for her Just Label It petition, which, according to Paltrow, had gathered 200,000 signatures in the six days since its launch.

“We would love to have by the time the House comes back in September a half million signatures,” Paltrow added.

In a statement Wednesday, Claire Parker, a spokesperson for the Coalition for Safe Affordable Food, criticized Paltrow’s involvement in the GMO-labeling campaign.

“Out of touch Hollywood celebrities like Gwyneth Paltrow want Congress to enshrine their lifestyle choices into law while ignoring the everyday realities facing American families,” Parker said. “This legislation has earned the backing of everyone from farmers to food banks. We are confident the Senate will stand with science and American families rather than the extreme agendas of Hollywood elites and that common sense and scientific consensus will win out over media spectacle.”

The organization also stressed the inconclusiveness of any negative health effects of GMOs on consumers, and said failure to pass the legislation could result in higher food prices. A recent Cornell University study found that allowing each state to develop GMO labeling would result in an average $500 increase in food costs to consumers per year.

“The fact is American farmers rely on this safe, proven technology to grow the food that feeds the world and the leading health and safety organizations – from the World Health Organization to the American Medical Association – have deemed GMOs safe,” Parker said. “This technology keeps food costs down, plain and simple.”

Paltrow, a longtime advocate for healthy eating habits, previously waded into the great American debate on food when she pledged to live on $29 worth of food stamps for a week to better understand the plight of poor Americans. The actress lasted four days before calling off the experiment.