More than 20,000 federal employees have informed the U.S. government they are willing to quit their posts under an incentive program that has a Thursday deadline, a U.S. official told Reuters on Tuesday.

Layoffs of federal workers would be "likely" if too few employees quit under the White House's deferred resignation program, the Washington Post reported on Tuesday, citing a memo from a General Services Administration official.

Over 20,000 employees plan to resign as the Trump administration aims to shrink the government and restructure roles, sparking outrage among civil servants.