President Donald Trump took his most consequential action against federal employee unions yet late Thursday, signing an executive order aimed at ending collective bargaining for government employees whose work include national security aspects.

The bipartisan Protect America’s Workforce Act aims to undo Trump’s recent order, which canceled a majority of agencies’ collective bargaining agreements.

Thousands of federal workers may lose the right to unionize after President Donald Trump signed an executive order that would ban employees in several departments and agencies from doing so.