(KCEN) -- Congress is working hard to avoid the fiscal cliff this Sunday.
Now there is a major setback, the deadline is two days away.
Sources close to the talks say a "chained CPI" is the major source of contention.
What is it? A CPI is the consumer price index.
It basically breaks down to how they increase and decrease benefits based on inflation in this case the benefits are social security, and its causing a fierce face off.
Another major sticking point continues to be the annual income level at which those tax increases should kick in.
The threshold has wavered from $250,000 to as high as $1,000,000.
Republicans argue the country doesn't have a tax revenue problem, it has a spending problem. We will have the latest on the fiscal cliff negotiations and what they mean for you.