Senate Minority Leader Mitch McConnell has asked Vice President Joe Biden to become involved in a last-minute effort to avert tax increases on virtually every worker. Top Senate Democrat Harry Reid acknowledged McConnell had made an offer last night but said "at this point we are unable to make a counter-offer."
The public exchange between the top negotiators on averting the so-called fiscal cliff injected a note of pessimism little more than 24 hours before taxes are set to go up.
Democrats said the Republican proposal called for changing the formula for calculating Social Security benefits increases.
McConnell said there is no single issue blocking an agreement but that "the sticking point appears to be a willingness, an interest, or courage to close the deal."