Suppose you had 500,000 workers who were expecting a pre-Christmas paycheck next week with an extra $86 in it.

And suppose you learn at the last minute that you cannot deliver the money to them as planned on Dec. 22.

And suppose you had to tell them to wait until early next year.

If you were the owner of such a giant firm, you would have several options. Among them:

(A) Jump off the nearest tall building

(B) Push your payroll chief off the nearest tall building

(C) Tell everybody the truth, apologize and wish them a happy Christmas!

That sounds like the very bad plot for a very bad pre-Christmas television special. Unfortunately, it is happening - or about to - in the government's largest agency, the U.S. Postal Service.

The postal workers, more than half a million of them, had been looking forward to the pre-Christmas payout for several months. It represents retroactive raise negotiated in their new contract that went into effect July 21. It took the unions a long time to ratify the contracts, so although workers now have gotten the raise in their checks - more on that later - they are still owed the amount of the raise from mid-July to mid-September.

say they were told, by USPS management, that the retroactive money would be made in the last check before Christmas. That would be next Friday. Postal officials now say they won't be able to make it, because of payroll problems.

Postal workers have been furious - as outlined here Nov. 29 - because of a series of payroll mix-ups that have plagued many of them most of the year.

Much of the problem results from a changeover to a new accounting system required by law. As a result, the workload of the Postal service in preparing time and leave records have literally doubled. As a result of that, thousands of employes have been overpaid, underpaid or not paid at all on time. The situation was so bad in some offices that postal officials were paying employees 70 cents on the dollar, postal money orders or in cash, because their checks were incorrect, or did not arrive at all.

Postal officials say they have worked hard to correct the earlier payroll problems. And they said that many of the "horror stories" cited in the press, and by union leaders, were old, overblown, or both. Now this.

Obviously the people who run the postal service are upset, embarrased and furious. But their unhappiness is thousands of employes who had been counting on the "biggie" check next week to help them complete Christmas shopping plans. IOUs may be big stocking stuffer items with the 12,000 Washington area postal families.