President Barack Obama issued a challenge to Republicans from the White House briefing room today, calling on Congress to pass an extension of a payroll tax holiday set to expire Jan. 1.

Obama, who spoke without taking reporters’ questions, said failure to reach agreement on the tax issue would hurt both individual families and the economy. Moreover, he questioned Republicans who voted last week in a political test vote against a surtax on millionaires as an offset for the payroll provision.

“Virtually every single Republican voted against that tax cut. Now I know many Republicans have sworn an oath never to raise taxes as long as they live. How can it be that the only time there’s a catch is when it comes to raising taxes on middle-class families?” Obama said. “How can you fight tooth and nail to protect high-end tax breaks for the wealthiest Americans and yet barely lift a finger to prevent taxes going up for 160 million Americans who really need the help?”

In his jobs plan, Obama had proposed both extending current law and expanding the holiday to include breaks for employers in addition to employees. He touted this from the podium today at the same time that Senate Majority Leader Harry Reid (Nev.) took the floor to announce a new Democratic plan that would drop the expanded breaks for employers. It would be paid for through a combination of means-testing of unemployment and food stamp benefits, spending cuts, and a more modest millionaires surtax.

The tax on those making more than $1 million a year, which Republicans consistently have rejected, will likely make the offering dead on arrival in the Senate GOP’s ranks — even though, as Reid noted, Republicans support the spending cuts as well as means-testing of government benefits.

Still, the move marks a shift closer to a potential compromise with time running out to tackle a packed legislative calendar.

Reid, whose speech was effectively interrupted by the president’s statement, echoed the basic gist of Obama’s plea.

“If Republicans block this proposal, raising taxes on American families by $1,000 next month will have an immediate impact on our economy,” Reid said. “It will halt very singularly our still-fragile recovery in its tracks and drag us back into a recession.”