Hospital services are increasingly reliant on doctors and nurses recruited from outside the UK and the EU, workforce data reveals.

According to research by the BBC Shared Data Unit, the Royal Free London NHS Foundation and the Whittington Health NHS Trust saw an increase in the share of non-UK or EU medical staff joining over the last seven years.

The Royal Free trust, which includes Barnet Hospital and Chase Farm, saw a 15.5% increase in the share of international medical staff joining between 2015 and 2021.

In the same period Whittington Health Trust saw a 7.5% increase in the share of medical staff from outside the UK and EU joining.

At the same time, the Royal Free saw an 8.7% and the Whittington a 7.6% decrease in the share of UK medical staff joining the services.

While the government said overseas recruitment has always been part of the long-term strategy, critics have warned this is an unsustainable way of recruiting in the long term.

Patricia Marquis, director for England of the Royal College of Nursing (RCN), said ministers must do more to reduce the "disproportionate reliance" on international recruits.

She said: “Our internationally-recruited nurses are, and have always been, invaluable to our health and care services, but ministers must do more to boost the domestic recruitment of nursing staff.

“One of the simplest ways to recruit and retain staff is to pay them fairly.”

While the NHS is recruiting more international doctors and nurses, it also faces challenges of retaining them.

The share of international medical staff leaving the Royal Free Foundation increased by 0.5% between 2015 and 2021 while the share of UK doctors and nurses leaving decreased by 6.6%.

In the same period, the Whittington Health Trust saw a 1.9% increase in the share of international medical staff leaving the trust while the share of UK medical staff leaving decreased by 10.6%.

The British Medical Association put this trend down to “punishing workloads” and the cost of visas.

Overall, the findings are broadly consistent with the wider national picture. The share of homegrown doctors joining English NHS services decreased by 11% between 2015 and 2021 and the share of UK nurses fell by 13%.

During the same period the share of international doctors joining English health services rose by 16% while the share of international nurses rose by 27%.

Nation-wide the share of EU medical staff joining English NHS services decreased from 11% in 2015 to 6% in 2021.

The Royal Free Trust saw a 6.7% decrease in the share of EU medical staff joining and a 6.1% increase in EU doctors and nurses leaving the trust during the same period.

In contrast, the share of EU medical staff joining the Whittington Health Trust actually increased by 0.1% between 2015 and 2021 while the share leaving decreased by 0.5%.

The Department for Health and Social Care (DHSC) said: “The government is committed to ensuring that the number of medical school places is in line with England’s workforce requirements.

“The government has funded an additional 1,500 undergraduate medical school places each year for domestic students in England – a 25% increase over three years – and there are record numbers of medical students in training.”

The government pointed out that the overall number of doctors had risen by 34% since 2010.

Danny Mortimer, chief executive of NHS Employers, said it was “high time for the government to commit to a fully-funded, long-term workforce plan for the NHS” to tackle “chronic workforce shortages”.

He said “relentless demand” was affecting staff due to vacancies which stood around 110,000 - “gaps which cannot and should not be filled through international recruitment alone.”

Kate Shoesmith, deputy CEO at the Recruitment and Employment Confederation (REC), said staff shortages in the NHS are “the worst they had ever been”.

A Royal Free spokesperson said: “We are extremely proud of our diverse workforce and we would like to thank all our amazing staff, who, every day, deliver extraordinary patient care.”

A spokesperson from Whittington Health NHS Trust said: “We are an open, non-judgemental and inclusive organisation that is committed to fair and consistent processes in our recruitment, training, promotion and access to services.

“We are committed to managing workforce pressures and ensuring our organisation is staffed with the appropriate number and skill-mix of staff to support the delivery of quality care.”