Some NHS hospital trusts have more than 1,000 staff vacancies while others have left crucial roles unfilled for up to two years, an investigation has revealed.
The ITV News probe across England, Wales, Northern Ireland and Scotland asked every acute trust to disclose how many staff posts were unfilled.
The biggest gaps were in nursing at each one of the 92 trusts that responded to freedom of information requests, the broadcaster reported.
The figures reveal the largest number of vacancies are at Barts in London, which has 1,732 unfilled roles but is also the biggest hospital trust in the country.
The Belfast trust, which manages eight of the city's hospitals, has 1,236 unfilled vacancies, with one role first advertised more than 18 months ago.
The trust at Barking, Havering and Redbridge has 849 vacancies, including 401 unfilled posts for nurses.
University Hospitals Coventry & Warwickshire NHS Trust has more than 1,042 vacancies, while at Central Manchester University Hospitals there are 965.
Consultants are in demand at North Cumbria, which has 48 vacant roles, East and North Hertfordshire, which has 23, and Calderdale and Huddersfield, where 44 roles remain unfilled.
Some trusts reported gaps in their intensive care units, such as Epsom and St Helier, which has 36 vacant roles.
Others reported that some jobs had gone unfilled for months or even years, including Derby Teaching Hospitals, where 44 vacant nursing roles and 12 consultant posts were first advertised at least six months ago.
Both Northern Devon Healthcare and Yeovil have vacant posts that were first advertised more than two years ago, while Great Western Hospitals has a role for a chemotherapy sister that has been advertised four times since August 2016.
In Scotland, the NHS Highland reported 357 vacancies, with one role that was first advertised more than 19 months ago.
ITV News said there are 636 vacancies across Wales, although it received no responses from the eight hospital boards in the country.
Health Secretary Jeremy Hunt told the broadcaster: "We are rightly saying we want to have much higher standards of care after the tragedy of Mid Staffs, we cannot allow hospitals to skimp on nursing staff.
"As a result of those changes we now have 15,000 more nurses in our hospital wards, 6,500 more doctors.
"But you can't magic up doctors and nurses, they need to be trained, we've increased the number of doctors we're training, we've made big reforms to nurse training."
Copyright (c) Press Association Ltd. 2017, All Rights Reserved. Picture (c) Peter Byrne / PA Wire.