Inspectors have raised several concerns about the NHS non-emergency ambulance service that covers Northampton, including infection control and the transport of children.
The Care Quality Commission (CQC) visit was carried out in November at the premises of Thames Ambulance Service Ltd, which transports Northampton patients for free to NHS appointments.
Although an inspection report has still not been published, a paper written for NHS Nene board members has revealed a long list of worries.
The report - which will be discussed in public on Tuesday (January 15) at Francis Crick House, Moulton, - says: "A risk summit led by NHS England was called in response to concerns identified at a recent CQC inspection (report to be published) and subsequent conditions that have been placed on the provider's CQC registration.
"The four main areas of concern identified were; staff training, infection control issues, transport of children, bariatric patients or patients with mental health issues and governance."
Both the CQC and NHS Nene declined to expand on the concerns.
However, the report says regular oversight meetings have been arranged and a quality improvement plan has been developed by Thames Ambulance Service, whose headquarters are in Essex.
It is not the first time that the ambulance service, which has contracts across the country, has been lambasted by inspectors.
This newspaper reported in 2017, when Thames Ambulance Service was awarded the contract for Northamptonshire, that a recent CQC report had found oxygen cylinders were stored unsecured overhead, posing a danger to patients and staff.
Ambulances were also found to be dirty, with discarded food, sweet wrappers and dust.
And previous to that, a CQC report in December 2016 revealed staff took a patient who was deteriorating straight to A&E instead of calling 999 and the patient later died.
A spokeswoman for NHS Nene said: “This was based on an inspection in another county and the Northants quality team have been visiting local bases regularly to ensure Northants patients are safe.
"We are not able to provide any further comment until the CQC report has been published.”