The employees had to knuckle under to the new manager's strict rules.
knuckle under
idiomTo cooperate or yield when forced or pressured to do so.
After weeks of resisting the new policy, the staff finally had to knuckle under when the company threatened to cut their bonuses.
Faced with the overwhelming pressure of the board of directors, the CEO was forced to knuckle under and accept the terms of the unpopular merger.