WASHINGTON – Hovering in the background of the “fiscal cliff” debate is the prospect of 2 million people losing their unemployment benefits four days after Christmas.

“This is the real cliff,” said Sen. Jack Reed, D-R.I. He’s been leading the effort to include another extension of benefits for the long-term unemployed in any deal to avert looming tax increases and massive spending cuts in January.

“Many of these people are struggling to pay mortgages, to provide education for their children,” Reed said this past week as President Barack Obama and House Speaker John Boehner, R-Ohio, rejected each other’s opening offers for a deficit deal.

Emergency jobless benefits for about 2.1 million people out of work more than six months will cease Dec. 29, and 1 million more will lose them over the next three months if Congress doesn’t extend the assistance again.

Since the collapse of the economy in 2008, the government has poured $520 billion – an amount equal to about half its annual deficit in recent years – into unemployment benefit extensions.

White House officials have assured Democrats that Obama is committed to extending them another year, at a cost of about $30 billion, as part of an agreement for sidestepping the fiscal cliff and reducing the size of annual increases in the federal debt.

“The White House has made it clear that it wants an extension,” said Michigan Rep. Sander Levin, the top Democrat on the House Ways and Means Committee.

Boehner did not include jobless benefits in his counteroffer response this past week to Obama’s call for $1.6 trillion in new taxes over the next decade, including raising the top marginal rates for the highest-paid 2 percent.

Long-term unemployment remains a persistent problem. About 5 million people have been out of work for six months or more, according to the Bureau of labor Statistics. That’s about 40 percent of all unemployed workers.