The National Retail Federation urged President Obama and Congress to come up with a plan to avoid the “fiscal cliff” by Thanksgiving, saying uncertainty over the pending combination of tax hikes and spending cuts threatens consumer confidence during the holiday shopping season that begins on Black Friday.

“Although most economists have focused on the impact to the economy in 2013, more immediate economic consequences could occur over the next few weeks if consumers lose confidence in the ability of policymakers to work together to solve tough problems,” NRF President and CEO Matthew Shay said. “Any disruption to consumer confidence and spending during this season could prompt a crisis for retailers and the millions of U.S. jobs the industry supports.”

“Rather than setting New Year’s Eve as its deadline, Washington needs to act quickly to set in place a framework for resolving this situation, preferably before Thanksgiving,” Shay said. “Demonstrating the ability to work in a bipartisan manner will ease consumers’ worries and avoid severe economic consequences during the single most crucial spending season of the entire year.”

Shay’s comments came in a letter sent today to the president and all members of the House and Senate.

Shay explained in the letter that many retailers make a quarter or more of their annual sales during the November-December holiday season. NRF is forecasting that holiday sales will increase 4.1 percent to $586.1 billion this year. In a recent NRF survey, about two-thirds of shoppers said the fiscal cliff and other economic concerns would affect their holiday spending.

“It is particularly important during this debate that lawmakers listen to small businesses, including the independent Main Street retail stores that are some of our nation’s most important job creators,” Shay said. “Many small business owners report their business income on their personal income tax returns and will be critically impacted by the outcome of this debate.”

Despite the prominence of large chains, 96% of U.S. retailers are small businesses with only a single location, and 26% of NRF members have less than $1 million in annual sales.