Early-childhood educators and advocates are bracing for a series automatic, across-the-board cuts set to hit a broad swath of federal programs on March 1, unless Congress can come up an agreement to avert them.

Education advocates say there’s a lot of uncertainty right now. They aren’t clear on the just how the cuts—which would slice $653 million out of the nearly $8 billion Head Start program, an early-education program for low-income children—would be implemented, if they are put in place. The cuts could mean 100,000 children could lose access to the program, according to an analysis by Democrats on the House Appropriations Committee.

But it’s unclear just how those cuts would be implemented, said Hannah Matthews, the director of early-childhood education at the Center for Law and Social Policy, a research and advocacy organization in Washington.

“For a while, nobody thought [the cuts were] really going forward,” so the Obama administration didn’t release guidance on just how it would carry out the reductions, she said. With the cuts only postponed rather than canceled, “we’re still in a precarious position.”

Some background: The cuts, which would slice about 8 percent off of a range of domestic programs, are known Inside-the-Beltway as “sequestration.” They would impact everything from the Federal Bureau of Investigation to cancer research to low-income heating assistance for the poor to the military. The cuts were put in place as part of a deal to raise the debt ceiling, back in August of 2011, and were part of the recent negotiations over the so-called fiscal cliff. That agreement postponed the cuts, which were set to hit on Jan. 2, until March 1.

Head Start isn’t the only early-childhood program that would be squeezed by the trigger cuts. A portion of the roughly $5.2 billion Child Care and Development Block Grant program would also be sliced, amounting to about $187 million. The program wouldn’t feel as much of a pinch as Head Start because parts of it are exempt from the trigger cuts.

But the squeeze would still be painful, said Helen Blank, the director of child care and early learning at the National Women’s Law Center in Washington. One in six eligible children receive funds under the Child Care and Development Block Grant program, she said.

At the same time, many states and local governments have also cut funding for early-childhood education, even as some policymakers begin to push for program improvement and clearer outcome measures.

Early-childhood advocates are watching other parts of the budget discussions, including funding for physical and mental health programs, said Yasmina Vinci, the executive director of the National Head Start Association in Alexandria, Va.

“A number of things are out there” for the families that receive Head Start, she said.

K-12 programs would also be hit by the trigger cuts. But, if the reducations go through, most of those programs would have a longer planning window. Title I grants to help districts cover the cost of educating disadvantaged kids and money for special education are “forward funded”, meaning that schools wouldn’t feel the effects until the fall of 2013. More here.