Patients will have to get used to seeing a pharmacist or physiotherapist instead of a family doctor because the NHS will never overcome its chronic lack of GPs, health experts say.

The NHS in England will no longer be able to care properly for patients without a major shake-up of GP services, the country’s three main health thinktanks argue in a report published on Thursday.

The one in five people who attend a GP surgery because of back pain and similar issues will increasingly have to be treated by a physiotherapist, and pharmacists will issue repeat prescriptions and conduct medication reviews, as part of a drive to relieve the pressure on overworked GPs.

The Royal College of GPs (RCGP) said the NHS should not to use other staff as “direct substitutes” for trained family doctors.

The report by the King’s Fund, Nuffield Trust and Health Foundation says: “The shortfall in the number of GPs is so serious that it cannot be filled at all. The only way forward is to use the skills of other staff, including pharmacists and physiotherapists, much more widely and routinely in and alongside general practice.”

Radical changes are needed because the NHS will not be able to train enough homegrown GPs or recruit the numbers needed from overseas to surmount the growing shortfall, said Richard Murray, chief executive of the King’s Fund.

“We can’t GP our way out of the problem. Around 20% of patients that see GPs are there for issues ... such as back pain. This is exactly what physiotherapists are trained for,” he said.

Trials of giving patients with musculoskeletal conditions rapid access to a physiotherapist rather than a GP had proved successful, and physiotherapists could take over “a significant workload” from GPs, he said.

The difficulties of recruiting enough medical graduates to train as GPs and retaining enough experienced family doctors mean the shortfall will almost triple from 2,500 to 7,000 by 2023-24, the thinktanks’ analysis predicts.

That widening gap means the NHS will need to hire 6,000 more physiotherapists and 3,000 more pharmacists to work in GP practices.

The RCGP voiced its unease. “The GP workforce faces significant challenges but we disagree that these are insurmountable,” said Prof Helen Stokes-Lampard, its chair.

“We are extremely grateful to the hard work, skill and dedication of the members of the wider practice team. But they are not GPs and must never be seen as direct substitutes or used to ‘fill the gaps’ long-term where numbers of GPs are insufficient.”

GP numbers have fallen by more than 1,000 since 2015, despite the government committing then to expanding the workforce by 5,000 by 2020.

NHS England recently set out plans to expand the range of health professionals who can be seen instead of a doctor by the 1 million patients a day who attend a GP surgery, including mental health therapists to treat anxiety and depression.

The thinktanks say a series of radical changes to NHS pay and training and immigration rules is needed “to avoid a vicious cycle of growing shortages and declining quality [of care]”. They include:

“Ethically recruiting” 5,000 extra nurses a year from abroad.

Exempting all healthcare staff from the government’s proposed £30,000 minimum salary for those wanting to come and work in the UK after Brexit.

Giving student nurses in England £5,200-a-year maintenance grants to help compensate for the abolition of nursing bursaries in 2016, which has led to a 4% fall in the number of applicants for nursing degrees.

Ensuring that NHS staff receive inflation-proof salary rises and no longer freezing their pay.

Closing the existing gender and ethnic pay gaps among NHS staff.

Spending £900m a year more on training and developing NHS staff by 2023-24.

The NHS doing more to help staff maintain a healthy work-life balance, for example through greater access to part-time working.

The NHS in England is short of more than 100,000 personnel – one in 11 posts. NHS national bodies will next month publish a long-awaited interim workforce implementation plan, which will set out potential ways of tackling the staffing crisis.

The Department of Health and Social Care said: “Across the NHS there are tens of thousands more doctors and nurses on our wards since 2010 and thanks to their dedication, thousands of patients get excellent, safe care every day.”