US President Donald Trump on Thursday moved to end collective bargaining with federal labour unions in agencies with national security missions across the federal government, citing authority granted to him under a 1978 law.

The order, signed without public fanfare and announced late on Thursday, appears to touch most of the federal government. The affected agencies include the departments of state, defence, Vterans affairs, energy, health and human services, treasury, justice and commerce and the part of homeland security responsible for border security.