AUGUSTA — The roughly 249,000 Mainers who receive federal funds to help them buy food could see that aid vanish if an ongoing dispute between state and federal agencies over a new program that urges recipients to put their photos on the cards they use to buy groceries.

Food and Nutrition Service — the U.S. Department of Agriculture agency responsible for the oversight of the federal Supplemental Nutrition Assistance Program, commonly known as “food stamps” — says several changes are necessary to Maine’s new photo ID requirement for SNAP recipients to keep it from running afoul of federal guidelines.

FNS also says the current implementation of the photo ID component could represent a civil rights violation.

Maine administers SNAP on behalf of the federal government, which funds the entire cost of benefits and roughly half the costs to run the program. FNS has threatened to pull its share of administrative funding, roughly $8.9 million, if Maine does not change the photo ID policy to meet its requirements. The agency has stressed that SNAP recipients’ benefits are not in jeopardy.

Still, Department of Health and Human Services Commissioner Mary Mayhew has said the state will continue with the current photo ID program, and said Monday that if the federal government curtails the administrative funding, the state could stop administering the program altogether.

“If the federal government takes a financial action against us that is baseless, we will have to question our ability to administer the program,” Mayhew said in an interview.

When asked by a reporter who would administer SNAP if Maine dropped the program, Mayhew said “the federal government would have to figure out another way. We simply cannot replace federal funding with state funding.”

However, one expert on SNAP said that if the state stopped running the program, it’s likely food assistance in Maine would stop flowing entirely.

Stacy Dean, vice president for food assistance policy at the Center on Budget and Policy Priorities, a left-leaning research and analysis group in Washington, D.C., said Monday that if Maine didn’t administer the program, there would be no one else available to do so.

“There’s nothing in the law that anticipates a state wouldn’t do it,” she said. “There’s no back-up plan. … Instead of reasonably arguing the rules of the program, [Maine] is playing with the ability of low-income people to purchase food.”

In 2013, the most recent year for which a report is available, Maine paid about $9.7 million in administrative costs, while the federal government paid about $376 million in benefits and administration to provide food assistance to low-income recipients in Maine.

If the state ended its participation in running SNAP, all those federal dollars would likely be left on the table, cutting off food assistance to the hundreds of thousands of SNAP recipients.

A DHHS spokesman, when asked for clarification of Mayhew’s statement, said the commissioner had nothing more to say on the issue and would not further address hypotheticals.

The dispute between Gov. Paul LePage’s administration and the feds has taken place in a series of letters over the past 10 months, and little progress on an agreement has been made.

FNS says the state rushed implementation of a flawed policy, and raised questions about the limited guidance given by DHHS to retailers and SNAP recipients, which it says has created uncertainty for beneficiaries and businesses that accept SNAP.

Specifically, the agency says DHHS isn’t doing enough to let clients know that the photo ID program is completely voluntary, or to let retailers know that they may not check an EBT cardholder’s photo as a means of verifying their identity.

In the most recent letter, dated Dec. 14, from Mayhew to the regional FNS office in Boston, the commissioner wrote that FNS has been “entirely unsupportive” in the state’s efforts to deter fraud and abuse.

“The series of impromptu visits, cease-and-desist letters and other opposition tactics thinly veiled as ‘serious concerns’ put a chilling effect on states who want to implement this common sense welfare reform,” she wrote.

Previewing the comments she made Monday about Maine’s future involvement with SNAP, Mayhew also wrote in the Dec. 14 letter that if FNS would not allow Maine to pursue its desired program reforms, the state would have to “re-evaluate” its partnership with the federal government.

Mayhew and LePage say the photo ID requirement will help ensure the integrity of the program and prevent illegal trafficking of electronic benefit transfer, or EBT, cards — the debit-like system used by welfare recipients to access SNAP funds and other benefits. DHHS implemented the photo ID requirement statewide in June, after a brief test run in the Bangor area in April.

Kurt Messner, the Northeast’s acting FNS administrator, said in a written statement Tuesday that his agency would continue working to ensure Maine is complying with federal law.

“As we explained to state officials earlier this year, a photo requirement involves complex legal, operational, and civil rights issues, and unfortunately, we found that the state’s implementation was confusing to many consumers and very vague to store clerks and as such did not meet the requirements,” he wrote.

Dean also said that it’s not unusual for states and FNS to disagree about a policy, or for the feds to use administrative funds as a “stick” to achieve compliance. Usually, she said, the state will eventually make changes to its program to comply with FNS guidance. But if they refuse, the issue often ends up in court, she said.

If that happens in Maine, it will be another in a growing list of fights between the LePage administration and the federal government that have found their way into a courtroom.

BDN Portland Bureau Chief Seth Koenig contributed to this report. Follow Mario Moretto on Twitter at @riocarmine.