President Bush, quietly floating a plan with big implications, wants schools to face consequences for falling short in science, just as they do in reading and math.

The president's proposal would require schools to make yearly progress in science, adding a third high-stakes subject to a No Child Left Behind law that has thousands of schools scrambling to meet federal goals.

Congressional leaders say they are willing to consider Bush's idea when the law comes up for renewal next year, but that's as far as they will commit.

Science already is part of the law. Starting in the 2007-08 school year, states are required to test students' science knowledge at least once in elementary, middle and high school. But nothing in the law requires holds schools accountable for science scores.

Bush wants to change that by applying a system of penalties for schools whose students do not improve their grasp of science. Such a move would affect millions of students nationwide.

"Given our philosophy that what gets measured gets done, this would be a natural way to emphasize the importance of science," said Assistant Education Secretary Tom Luce. "We do think it's important to have consequences."

In reading and math, those consequences have made the yearly test scores a huge priority. Schools that get federal poverty aid and miss even one academic target face penalties that get tougher each year — from letting students transfer to firing employees.

The same could apply in science.

That idea is winning support from science advocates, who say it would force schools to expand curriculum and put more time into training children for a technical world. But critics of how the law measures progress say adding science to the mix could be a nightmare.

Bush's idea is buried inside his new competitiveness plan, which includes expanding reading and math testing to high school. The idea had gone nowhere on Capitol Hill.

But in science, Bush is tapping into a fresh area of concern. Faced with slipping U.S. performance in science education and research, Congress is demanding action.

Within Bush's party, the House education committee chairman, Rep. Howard McKeon, R-Calif., has an open mind about requiring schools to show gains in science, spokesman Steve Forde said.

In the Senate, education committee chairman Mike Enzi, R-Wyo., wants input from people affected by the law, including parents and teachers who say kids are tested enough. "I don't think we're close to making a decision," said his spokesman, Craig Orfield.

Democrats who helped Bush pass the law in 2001 have offered wait-and-see responses, too.

Sen. Edward M. Kennedy, D-Mass., is not opposed to adding science to how schools are judged. But a spokeswoman said Kennedy does not think the change should happen until states have a chance to get high-quality tests in place and more training for their teachers.

One clear supporter is Rep. Rush Holt. A New Jersey Democrat with a background in physics, Holt has pushed for judging schools on their science scores when testing begins. At a hearing last fall, he grilled Education Secretary Margaret Spellings for a commitment.

"It is as important as reading and math," Holt said in an interview. But he says Congress may balk because they're getting an earful about problems with the current law.

Among those problems is how progress is measured. Many educators don't like the reliance on tests, or how missing one academic goal labels the whole school as "needing improvement."

"Let's get it right first. Then we can start talking about bringing on science or whatever subject they want to talk about," said Rob Weil, deputy director of educational issues for the American Federation of Teachers.

Many local school leaders also want a better way to measure progress — plus more federal support for education — before they get enthusiastic about being graded on science.

But Inez Liftig, an eighth-grade science teacher in Fairfield, Conn., said the idea is solid: Schools should face consequences if they don't raise achievement.

"What I find myself doing year after year is shoring up the foundation that should have been there had the curriculum in elementary school been followed," Liftig said. "Because science is not a mandated item, it get pushed to the end of the day."