– More than 500,000 children would lose automatic eligibility for free school meals under a rule proposed last week by the Agriculture Department intended to tighten access to food stamps.

The effect on school meals, revealed by Rep. Robert Scott, D-Va., chairman of the House Committee on Education and Labor, was not disclosed when the proposed food stamp rule was published last week. Agriculture officials said the new rule would close a loophole that they said allowed people with high incomes and accumulated assets to receive food stamps. The Agriculture Department said the proposal would cut off an estimated 3 million people from food stamps, a figure that critics said would include tens of thousands of working poor families.

But the department said nothing about children from those same households who would automatically lose eligibility for free meals at school.

“It would very much be a double whammy for those children,” said Lisa Davis, senior vice president of the No Kid Hungry campaign.

Scott said his staff were made aware that students would lose their automatic eligibility for free school meals in a phone call July 22 with staff members from the Agriculture Department. In a letter, he implored Sonny Perdue, the agriculture secretary, to disclose the figures as part of the department’s regulatory impact analysis and restart the 60-day comment period.

“The effect on school meal eligibility represents an important technical finding that must be made public so that stakeholders have the opportunity to comment on all aspects of the rule’s impact,” Scott wrote.

The Agriculture Department has not revealed the number of children who could be affected by the proposal.

The department has said that the proposed rule for the Supplemental Nutrition Assistance Program (SNAP), commonly known as food stamps, “ensures SNAP benefits go to those who meet the eligibility criteria as outlined by Congress, not millionaires or those who simply received a referral to a nonworking 800 number.”

To justify the rule, conservatives point to a millionaire from Minnesota, Rob Undersander, who said he received food stamps for 19 months even though he had significant assets.

Jonathan Butcher, a senior policy analyst at the conservative Heritage Foundation, said the rule would ensure that the government was “providing resources to the children who are in need and not providing resources to those who are not in need.”

Right now, households that receive benefits or services from another federal welfare program, Temporary Assistance for Needy Families, are automatically eligible for food stamps in 39 states, the District of Columbia, Guam and the Virgin Islands. In some of those states, households with gross incomes up to 200% of the poverty line — which would be about $50,000 for a family of four — are automatically eligible for food stamps. Children in those households are automatically eligible for free school meals, too; over 8 million children were directly certified for free school meals in this way in the 2016-17 school year. Not all of those who automatically qualify for food stamps or free school meals necessarily receive them, though.

Under the proposal, fewer families would automatically qualify for food stamps, and in turn, fewer children would get free school meals. Children in households with gross incomes between 185% and 200% of the poverty line would no longer be automatically eligible for any food assistance at school. And children in households with gross incomes between 130% and 185% of the poverty line would be eligible for only reduced-price meals. Families would be charged a maximum of 30 cents for breakfast and 40 cents for lunch.

“Even that reduced price fee is very, very burdensome on families that are struggling to make ends meet,” Davis said.

The Agriculture Department estimates that schools serve about 34 million free and reduced-priced breakfast and lunch meals a day. Critics of the change worry that losing free school meals would negatively affect the children’s academic performance and health.

Healthy school meals “are proven to support academic success, obesity prevention and overall student health,” said Gay Anderson, president of the School Nutrition Association.

Critics also worry that the proposal would worsen the debts already being accrued by families who have a hard time paying their school lunch fees. Episodes of “lunch shaming” — in which children are publicly reprimanded for being unable to pay a school lunch bill, including by having their food thrown away — have occurred and have received wide media coverage.