While Congress has the capacity to move swiftly when motivated, the leaders of the House and Senate have left themselves little time for what could be a complicated day of procedural maneuvering in the event of an agreement.
Boehner has insisted that the Senate act first, but that chamber does not begin legislative business until about noon Monday.
Other Business Also on Agenda
And the cliff is not the only business on the House agenda. The top leaders in both parties on the House and Senate Agriculture committees have agreed to a one-year extension of the expiring farm law to head off a possible doubling of retail milk prices to $7 or more a gallon in early 2013. Senate Agriculture Committee Chairman Debbie Stabenow, D-Mich., indicated the House could vote on the bill soon, though House leaders have not yet agreed to put the bill on the floor.
(Read More: Leaders Agree to on Deal Stop Spike in Milk Prices)
Also, relief for victims of super storm Sandy is waiting in line in the House, though the House could still consider a Senate bill on assistance for the storm until Jan. 2, the last day of the Congress that was elected in November 2010.
(Read More: Somewhere Over the 'Fiscal Cliff'... Skies Are Blue)
Expiring along with low tax rates at midnight Monday are a raft of other tax measures effecting tens of millions of Americans.
A payroll tax holiday Americans have enjoyed for two years looks like the most certain casualty as neither Republicans or Democrats have shown much interest in continuing it, in part because the tax funds the Social Security retirement program.
The current 4.2 percent payroll tax rate paid by about 160 million workers will revert to the previous 6.2 percent rate after Dec. 31, and will be the most immediate hit to taxpayers.
A "patch" for the Alternative Minimum Tax that would prevent millions of middle-class Americans from being taxed as if they were rich, could go over the cliff as well. Both Republicans and Democrats support doing another patch, but have not approved one.
(Read More: Middle Class Gets 'Cliffed' by Huge Tax If No Deal Reached)
At best, the Internal Revenue Service has warned that as many as 100 million taxpayers could face refund delays without an AMT fix. At worst, they could face higher taxes unless Congress comes back with a retroactive fix.
After Tuesday, Congress could move for retroactive relief on any or all of the tax and spending issues. But that would require compromises that Republicans and Democrats have been unwilling to make so far.
Obama said on Sunday he plans on pushing legislation as soon as Jan. 4 to reverse the tax hikes for all but the wealthy.
