The RCN has heard on a weekly basis from nurses with safety concerns on its Raising Concerns, Raising Standards hotline.
Since the beginning of this year, nurses have increasingly reported concerns about decisions driven by financial concerns.
RCN chief executive and general secretary Dr Peter Carter said: 'It is deeply worrying that not a week goes by without a nurse calling in with serious concerns. It is a sad indictment of the pressure nurses find themselves under that any nurse says they have insufficient time available to complete work safely.'
An RCN survey last year found 78% of nurses were concerned about victimisation or a negative effect on their career if they reported concerns.