For the first time in decades, many states could begin turning away eligible applicants from an assistance program that provides low-income women and their children critical access to food.

The Special Supplemental Nutrition Program for Women, Infants, and Children, a federally funded program known as WIC, has traditionally received bipartisan support from lawmakers. But the broader push for spending cuts among some House Republicans has threatened the program’s ability to provide benefits to every eligible person who applies.

The Agriculture Department warned last month that the program could see a $1 billion shortfall and that millions of eligible pregnant and postpartum women and their children could risk missing out on nutrition assistance this year if Congress does not increase funding.

Some House Republicans have pushed for maintaining funding at roughly similar levels as the past few years, despite a recent surge in participants. The effort is part of a larger push among conservatives to rein in federal spending in an attempt to address the nation’s rising debt load.

Lawmakers have been divided for months over federal spending levels, raising the risk of a partial government shutdown this month. Congress passed a stopgap measure in November, which allows states to continue normal operations for the WIC program. But lawmakers are running up against a Jan. 19 deadline to extend funding.

Senate and House leaders said on Sunday that they had reached an overarching agreement on total government spending. That deal has met resistance from hard-right lawmakers, though, and it is unclear whether Congress will increase funding for WIC.