Almost £30 million was spent last year by the ambulance service that serves Buckinghamshire, Berkshire and Oxfordshire on paying private ambulances and taxis to transport patients due to a lack of frontline staff.

Around half of that was spent on emergency call outs alone, with South Central Ambulance Service NHS Foundation Trust (SCAS) blaming a national shortage of paramedics and the high cost of living in the region for its need to turn to private firms.

The figures, which are the highest in the UK, reveal the county's ambulance service paid a total of £15,382,218 for 999 work plus £12,328,134 for patient transfer in 2018/19.

SCAS also spent £1,800,000 during the same period on taxis.

It comes after the Care Quality Commission published a report earlier this year warning there was a risk to patients' safety due to the use of private ambulances.

The watchdog stated it had found 'pockets of good practice' but 'remain[s] concerned about the overall standard of care'.

A statement from SCAS, however, maintained its use of private ambulances and taxis did not impact the treatment patients received.

It said: “Private providers support SCAS to be able to deliver a high-quality, responsive emergency 999 service.

"SCAS is one of the best performing ambulance trusts in England when measured against national performance indicators under the Ambulance Response Programme, as well as being a leading trust in clinical outcomes for patients suffering cardiac arrest, stroke, major trauma and other life-threatening injuries and illnesses."

It added SCAS recently became the first ambulance service to roll out an Electronic Patient Record system to all its private providers, so that every patient in its area received the 'exact same high-quality care' whether they were treated by a SCAS crew or one from a private ambulance.

The trust was rated as 'good' following following its most recent inspection by the CQC.

A report, which was published in November, praised the trust for making changes to ensure the organisation was more effective but 'still remains patient centred'.

Explaining its need to plug staff shortages, SCAS stated: "Private providers ensure that despite vacancies in our frontline workforce (due to a national shortage of paramedics and exacerbated in our region by operating in a high-cost living area and the need to maintain salary levels that are agreed at a national level) we can ensure that the expected level of demand for our 999 service can be met."

SCAS has managed to cut the money spent on hiring private ambulances for patient transfer by around £2.5m in the past 12 months but has seen a similar rise in their use for 999 work.

Payments for taxis have also gone up by £100,000.

Overall, the figures, which were obtained via a Freedom of Information request by the Press Association, are just over a million pounds down on 2017/2018, which totalled £30,548,754.

The increase in SCAS using private providers for 999 work follows a trend highlighted by the CQC in its March report looking at their use by NHS trusts.

The agency said over the last decade an 'increasing number' of independent ambulance providers had entered the emergency sector but that the quality 'varies widely'.

Ellen Armistead, CQC’s Deputy Chief Inspector of Hospitals and lead for ambulance services, at the time said: “Those who deliver and commission care must learn from the services that are getting it right so that people are protected from risk and can have confidence in the quality of care they receive from independent ambulance services across the country.”

Private ambulances are hired from private firms as well as charities such as St John Ambulance and the Red Cross.