Prosecutor General Ruslan Ryaboshapka has already fired more than 400 prosecutors, or around a third of all staff.
Some prosecutors have told Reuters that many of those sacked had refused to sit the exam in protest at what they see as a purge designed to cement new President Volodymyr Zelenskiy’s political control of the service.
Zelenskiy has said the overhaul is essential because the office is widely distrusted by Ukrainians and had been seen as a political tool for the well-connected to punish their enemies.