The Care Quality Commission (CQC) in the UK has urged Serco to take necessary action to improve its out of hours GP services in Cornwall and the Isles of Scilly.
The CQC inspectors reported that Serco is failing to meet four of the essential standards of quality and safety and it was given 14 days to provide a report detailing the measures to be taken to achieve compliance.
CQC South deputy director Ian Biggs said at least half a million people depend on the service, so it is vital that it is properly staffed with properly qualified GPs who are available when people need them.
"At times, Serco has not had enough doctors on duty and it is hardly surprising that people have complained. Asking GPs and their drivers to work such long hours should be a last resort," Biggs added.
"We haven't found that the company have been deliberately misleading the people of Cornwall about their performance, although quite clearly the system of monitoring performance is unreliable."
CQC identified concerns relating to eight outcomes such as respecting and involving people who use services, safeguarding, levels of staffing and staffing issues, the care and welfare of people, arrangements for assessing and monitoring the service, and their complaints procedures.
Inspectors concluded that not all staff were trained in safeguarding vulnerable adults and children and the provider did not have an effective system to assess and monitor the quality of service that people receive.