The campaign groups says the rules will turn over key food safety inspection functions to poultry companies with limited oversight by USDA inspectors.

“These rules essentially privatise poultry inspection, and pave the way for others in the meat industry to police themselves,” said Wenonah Hauter, executive director of Food and Water Watch.

“The USDA’s decision to embrace the scheme – an initiative lobbied for by the meat industry for more than a decade – flies in the face of the agency’s mandate to protect consumers. What’s more, we believe it’s illegal.”

In its suit, Food and Water Watch says the new system violates the Poultry Products Inspection Act (PPIA), a law passed in 1957 that gives USDA the authority to protect consumer health and welfare by assuring that poultry products are wholesome, not adulterated, and properly marked, labelled and packaged.

The organisation alleges that NPIS violates a number of statutory requirements, including the PPIA’s prescription that federal government inspectors, and not poultry slaughter establishment staff, are responsible for condemning adulterated young chicken and turkey carcasses.

The suit states that the NPIS rules also violate the PPIA’s requirement that federal inspectors supervise slaughter establishment reprocessing, which is done to avoid the condemnation of adulterated birds - essentially removing problematic chicken parts to allow the rest of the bird to pass inspection, the organisation said.

The suit is being brought by Food & Water Watch, on behalf of itself and its members, who include the two other individual plaintiffs, Margaret Sowerwine and Jane Foran.

Defendants are Agriculture Secretary Tom Vilsack and other officials from the USDA and its Food Safety and Inspection Service.

The suit says that consumers will be hurt by NPIS, and notes objection with the process by which the rule was implemented. For example, there was no opportunity for oral comments at a public meeting.

The group alleges that there were also elements that changed in the final rule that were not even hinted at in the proposed rule for public review.

Under the new system, company employees will be charged with removing adulterated product from slaughter lines at their own discretion. The new rules do not mandate training for these company inspectors; whereas USDA inspectors undergo extensive training to allow them to fulfil these tasks under the current inspection system, Food and Water Watch said.

In its comments submitted to the USDA on 29 May this year, Food and Water Watch detailed the results of an analysis that it had done with federal government documents obtained through a Freedom of Information Act request.

The analysis found that for 11 young chicken and three young turkey plants participating in a pilot programme used to design this change in inspection rules, for the first shift of production in those plants from March to August 2011, establishment personnel missed more than 30 per cent of conditions on chickens that includes blisters, bruises, external mutilation, fractures, sores, and scabs, and 60 per cent of dressing defects such as the presence of feathers, oil glands, and trachea.

The same analysis found that company employees missed more than 30 percent of conditions on turkeys that includes blisters, bruises, external mutilation, fractures, sores, and scabs, and 87 per cent of dressing defects such as the presence of feathers, oil glands, and trachea.

“USDA’s new system will harm consumers and reverse 100 years of effective government regulation of the meat industry,” said Ms Hauter.

“It’s essentially a return to Upton Sinclair’s The Jungle. It’s a huge step backwards for our food safety system.”