The Republican-led House of Representatives, in an election-year showdown with President Barack Obama, will vote on Friday to extend for 12-months a low interest rate for federal student loans, the top Republican said on Wednesday.

House Speaker John Boehner made the surprise announcement, adding that the $6 billion extension would be funded with money from what he described as a "slush fund" in Obama's healthcare overhaul law.

Boehner's declaration came after Obama, at campaign-style events, hammered Congress to extend the loan rate before it doubles on July 1 to 6.8 percent for more than 7.4 million students.

"This week, the president is traveling the country, on the taxpayers' dime, campaigning and trying to invent a fight where there isn't one," Boehner said.

He would pay for the extension by taking money from a fund established by Obama's healthcare overhaul to finance wellness programs and public health activities to prevent illness.

Republicans won control of the House in 2010, promising to repeal the healthcare overhaul. They have been unable to do so, but have repeatedly sought to chip away at it.

Obama and his fellow Democrats in Congress want to pay for the extension by plugging a loophole that they say wealthy professionals use to avoid payroll taxes on their earnings.