WASHINGTON - - U.S. holiday retail sales this year are the weakest since 2008, after a shopping season disrupted by storms and rising uncertainty among consumers.

A report out Tuesday that tracks spending, called MasterCard Advisors SpendingPulse, says holiday sales increased 0.7 percent. Analysts had expected sales to grow 3 to 4 percent.

Much of the shortfall comes from Superstorm Sandy, which caused sales declines after striking the East Coast in late October.

And consumers grew increasingly nervous as lawmakers failed to reach a deal to head off tax increases and government spending cuts set to take effect in early 2013.

The SpendingPulse number tracks sales of popular holiday goods, including electronics, jewelry and clothing, in the two months before Christmas. That's a crucial period for retailers.