Kathryn Watson documents for the Daily Caller new congressional efforts targeting federal employees who spend all day doing union work.

Republicans on the House Committee on Oversight and Government Reform (HOGR) are demanding more information on all federal employees who collect taxpayer-funded salaries while conducting business for government worker unions.

In what could be the precursor to a coming legislative battle over “official time,” panel chairman Rep. Jason Chaffetz of Utah and his committee colleagues fired off letters to agency heads Friday, giving them until Feb. 26 to disclose the names, positions and salaries of any employees who work full- or part-time on union activities while on the taxpayer’s dime.

The letters come as the House considers a bill requiring the Office of Personnel Management (OPM) produce an annual report on federal employees’ use of official time, including the exact ways time was used. The federal personnel agency publishes sporadic reports on official time, but hasn’t issued one since 2012.

Rep. Dennis Ross , a Republican from Florida and former chairman of the HOGR subcommittee on the federal workforce, is sponsoring a new bill to force more details on official time from OPM.

A November 2014 Government Accountability Office report sampled 10 agencies that account for about half of all official time usage, and found nearly 400 employees worked on union activities full-time. Another 300 worked on union duties at least half the time.