It’s certainly not a decrease, but the National Retail Federation’s (NRF) holiday report doesn’t have much good news for retailers this holiday season.

The group projects $586.1 billion in sales during the November and December holiday period — a 4.1 percent increase from last year. That compares with a 5.6 percent increase in 2011 and a 5.5 percent jump in 2010.

What’s causing the potential slowdown in holiday sales?

“It’s the uncertainty about where the economy is going, the uncertainty at the federal level about the fiscal cliff, the absence of a path forward from the president and the Congress,” the group’s president, Matthew Shay, said in an interview with Reuters.

As we’ve reported, the fiscal cliff, a set of automatic cuts likely to hit on January 2, would end a series of tax breaks and force cuts to a number of government agencies unless Congress makes a deal before then. Many associations have asked for action to fend off these cuts.

In related news, NRF’s digital arm, the online-shopping-focused Shop.org, released its own projections for 2012 — and they predict a 12 percent increase in sales this holiday season, reaching as high as $96 billion.

Do you think the fiscal cliff could put a damper on the holiday season? Leave us your thoughts in the comments.

(Photo via sxc.hu)