WASHINGTON — Pushing back against Obama administration efforts to help states sidestep some provisions of No Child Left Behind, Republicans said this week that a new report questions whether the Education Department has the authority to offer states waivers from parts of the law.

A recent report by the nonpartisan Congressional Research Service said Education Secretary Arne Duncan could legally grant the waivers for some parts of the law, but others cannot by waived and some could be open to challenge in court.

Duncan’s plan would allow state or local school districts to apply for waivers to circumvent the controversial education law is reworked.

But committee Republicans said that Congress, not the administration, should deal with the issue. No Child Left Behind, which was proposed by President George W. Bush and approved by Congress with strong bipartisan support, requires statewide achievement standards, annual assessments of student progress and teacher accountability. It became law in 2002; it has been reauthorized on an annual basis since 2007, rather than the more typical five-year authorization, which is what a House committee is now considering.

“I remain concerned about the secretary’s proposal to grant waivers in exchange for reforms not authorized by Congress,” said Minnesota Republican John Kline, chairman of the House Education and the Workforce Committee. “The CRS report illustrates the urgent need for the secretary to share the specifics of his proposal with individual schools and Congress.”

By law, waivers can be granted only on a case-by-case basis, must have specific and measurable goals and must be carefully monitored to ensure they improve the quality of instruction.

The report, which was requested by the committee, said that if secretary, as a condition for granting a waiver, required states to take actions not already authorized by Congress, the waiver would be far more vulnerable to a legal challenge.

However, it said the secretary does not have the authority to issue waivers unless states apply for them. This challenges some new regulations, such as the School Improvement Grant Program of 2010, which require funds to go primarily to schools performing in the lowest 5 percent. According to the report, the Education Department can only invite state and local agencies to apply for waivers, not force them.

The report comes on the heels of a letter from Kline to Duncan on June 23, warning that the waiver plan could cause additional confusion for schools and parents and undermine Congress’ efforts to fix problems in No Child Left Behind through legislation.

“We strongly believe any initiative that could exacerbate the frustration and uncertainty facing schools is the wrong direction for our nation’s education system,” the letter said.

A statement from the committee said Tuesday the letter, which asked for a response by July 1, was so far unanswered.

In announcing the waiver plan, Duncan said Congress has taken too long to address problems with No Child Left Behind.

“Our children get only one shot at an education and they cannot wait any longer for reform,” Duncan said in his June 13 statement. “We must fix No Child Left Behind, not in Washington time, but in real people time.”

Congressional Republicans are not alone in their concern over the waiver plan. The presidents of the two largest teachers’ unions also have been critical, saying that the use of waivers would be complicated and distract from bigger problems.

“[Duncan] has clearly signaled that any relief would be coupled with more unmanageable hurdles for schools and students,” said Dennis Van Roekel, president of the National Education Association, in a statement. “Our students and schools need regulatory relief, not more hoops to jump through on a never-ending obstacle course.”

American Federation of Teachers President Randi Weingarten said the waiver process would create a disincentive to reauthorize—and fix—the Elementary and Secondary Education Act.

“We need to figure out how to get this done in the right way,” she said, “that focuses on incentivizing what do to help all kids not just some kids succeed.”