An appeals court has paved the way for a likely showdown in the US supreme court over presidential power after reinstating two federal agency heads fired from their posts in Donald Trump’s all-out assault on the government bureaucracy.

The Washington DC court of appeals ordered that Cathy Harris and Gwynne Wilcox be restored to the positions with the Merit Systems Protection Board and the National Labor Relations Board (NLRB) respectively. The ruling overturned a previous verdict by a three-judge panel which had ruled that their dismissals – which had been earlier overturned under legal challenge – were indeed legal.