Obama, a U.S. senator from Illinois, made the accusation Saturday in Newark, N.J., where he was speaking to members of the AARP, The Hill reported.

Obama said McCain would cut cost-of-living adjustments or the raise the age at which people could receive the benefits.

"John McCain said that the way Social Security works is, and I quote, 'an absolute disgrace.' Wrong," Obama said. "For millions of Americans, it's the very difference between a comfortable retirement and falling into poverty.

"Privatizing Social Security was a bad idea when George Bush proposed it, and it's a bad idea today."

McCain spokesman Tucker Bounds denied the claim, saying, "John McCain has always promised to fiercely protect social security benefits and Barack Obama's willingness to recklessly misinterpret the facts to scare seniors for political points is the divisive type of behavior that has ruined Washington and shows why Obama is the absolute wrong man to fix it."