Even before most federal agencies had shared their plans for a possible government shutdown this week, the White House delivered a message that resonated across the bureaucracy: a funding lapse could be used as an opportunity for even more layoffs.

With days left before the government runs out of money at 12:01 a.m. on Wednesday, federal workers were grappling with a deepening sense of uncertainty about the ramifications if congressional leaders cannot come to an agreement over the budget.

Agencies have been slow to to post their contingency plans for how they would operate. And the threat issued by the White House that the administration would use a shutdown to fire more workers has fueled even more anxiety across the federal work force, already stretched thin by the administration’s mass terminations and cuts.

Around 300,000 employees are set to be off the payroll by the end of the year. The federal workers who remain are now facing the prospect of going without pay for an indefinite period — or possibly even losing their jobs.