"An unsustainably high level of vacancies, work pressures and potential risks to patient care" is one of a number of concerns raised by the NHS Pay Review Body in the organisation's report on Agenda for Change.
"There are some plans in place, which contain significant risks, to bridge that (workforce) gap by 2021," the report continues, "but the gap will persist to 2027 if there is no action on workforce numbers, productivity or service redesign."
Noting that the recent pay agreement with the health service unions is the "most significant change to the AfC structure since its introduction in 2004 (which) covers 1.2million staff (FTE) across the UK and affects a pay bill of over £43billion," the report says "workforce issues are of the most significant concern and of the highest priority for healthcare providers.
"The evidence suggests that pay restraint has contributed to efficiency savings within the NHS, but is not contributing to the recruitment, retention and motivation of NHS staff."
The report identifies staff retention risks as "high workload, insufficient flexible working, leadership capacity and medium term reward."
The PRB gives high praise to the unions in the pay negotiations, commenting that "There has been considerable effort and goodwill by the NHS Staff Council in reaching a three-year agreement on AfC pay in England.
"The agreement provides a balanced package of pay reforms that aim to address the concerns of both AfC staff and employers, and to contribute to the sustainability of the workforce. It includes enhanced starting pay, protection for the lowest paid, restructuring of pay bands and improved pay progression supported by renewed performance management."
The report takes a dim view of the loss of student bursaries in England, which "has been followed by a 20% reduction in applications to AfC-related health degrees in the UK in 2017. There may be risks over the quality of entrants if the number of applications continues to diminish."