Federal workers should report to work today, a White House spokesman said late last night, because President Reagan is expected to sign the emergency spending bill today that will keep the government operating.

White House spokesman Anson Franklin said shortly before midnight that the bill was to arrive at the White House "soon," that the Office of Management and Budget had recommended that Reagan sign the bill, and that the signing probably would be today.

As the bill made its way through Congress yesterday, federal workers received confusing and sometimes contradictory instructions on what they should do today. If the president had vetoed the spending bill by this morning, employes in agencies and departments where budgets have not already been approved were instructed to stay home.

But earlier in the day, the Office of Personnel Management told federal employes to come to work today no matter what and wait for any official word about possible furloughs. OMB countered that decision late yesterday, despite OPM's contention that employes should get the word, whatever it is, in an organized fashion, and not run the risk of further confusion about what to do.

Although many federal agencies and departments technically ran out of money at midnight last Friday, government employes worked through the day yesterday while waiting to see what Congress and Reagan would do with the funding measure.

The last time a partial shutdown resulted from a spending bill veto, the costs of shutting the government down were more than $50 million, according to the General Accounting Office. For this reason, a partial shutdown scheduled to begin at noon yesterday was postponed with the hope that it would all work out -- somehow.

While that attitude of faith may change abruptly should Reagan veto the funding bill, federal workers at their desks yesterday seemed to have grown accustomed to funding crises, faced twice before during this past year.