The White House's Office of Personnel Management on Thursday ordered the heads of all federal agencies and departments to immediately crackdown on overuse of "official time," the practice of allowing federal workers to conduct union business while still being paid for their government job. President Trump signed an executive order in May calling for the practice to be curtailed, citing cases where some employees did nothing except official time as proof that it was being abused.

A letter to all heads of departments and executive agencies from OPM Director Jeff Pon said they should cancel existing agreements with unions on official time and start from scratch. "[A]gencies shall take steps to modify (collective bargaining agreements) and other agreements at the soonest permissible opportunity to ensure that unrestricted grants of taxpayer-funded union time are eliminated," Pon said.

The OPM letter states that government workers can spend no more than 25 percent of their total paid time on official time and cannot use the time to lobby the government on official time or to "prepare or pursue" worker grievances, all previously common practices. It sets the total annual amount of official time hours allotted for a union at no more than one per member of the union. It also directs federal agencies to strictly monitor and report on the practice and to make those reports public.

Official time was first allowed under the 1978 Civil Service Reform Act and has been traditionally viewed as a trade-off for certain limitations put on federal worker unions, such as prohibitions on striking. Its use is widespread, and it increased during former President Barack Obama's administration.

A May report by the OPM put the cost at $175 million in 2016, up from $162 million in 2014, the last time the practice was surveyed. The total number of official time hours was 3.6 million, up 100,000 hours from 2014.

The directive makes clear that the administration views official time as, at best, a necessary evil and directs heads of agencies to adopt that attitude too. "[A]gencies should take the view in collective bargaining negotiations that taxpayer-funded union time is not ordinarily considered to be reasonable, necessary, in the public interest, or consistent with effective and efficient Government," it said.

Unions representing federal workers have defended official time, arguing it makes addressing worker-related issues cheaper for taxpayers by having people ready to deal with them. The unions claim the White House is trying to politicize the issue.

A representative for the American Federation of Government Employees could not be reached for comment.