The controversy is propelled by a significant public opposition supported by a minority of professionals,[16] including researchers, dental and medical professionals, alternative medical practitioners such as chiropractors, health food enthusiasts, a few religious groups (mostly Christian Scientists in the U.S.), and occasionally consumer groups and environmentalists.[17] Organized political opposition has come from libertarians,[18] the John Birch Society,[19] and from groups like the Green parties in the UK and New Zealand.[20][68][72]