WASHINGTON — For the first time in 14 years, the Senate on Thursday approved a revised version of No Child Left Behind, the signature Bush-era education law that ushered in an era of broadly reviled, high-stakes standardized testing.

But the passage of the bill on a vote of 81 to 17, coming just a week after the House narrowly passed its own version, sets up a showdown between the two chambers, and leaves the fate of a final measure in doubt.

Both bills return some key power to local governments but differ over the role of the federal government and funding allocations.

Congress has repeatedly failed in its efforts to rewrite the law over the last several years.

At the heart of the debate between Democrats and Republicans is the appropriate role for the federal government in education programs, which are largely a function of state and local governments.