Around 10 percent of areas in England were left without GP cover either overnight or on weekends at some point during last year, an investigation by Pulse has revealed.

Out of 104 commissioners of out-of-hours services responding to the publication's request for data under the Freedom of Information Act, ten said there were times when patients were left with no such cover during 2016 because of "chronic" staff shortages.

In Peterborough, nine shifts serving 230,000 patients were left uncovered last year, during which time all children were diverted straight to A&E, while in Doncaster nurses and higher-skilled paramedics were handling an area housing 300,000 patients on three occasions, because of a shortage of GPs available out-of-hours, the investigation found.

According to current national quality standards, all patients should be able to see a GP at any time if it is clinically appropriate, but there have been signs of cracks in the out-of-hours system for some time, and the situation could deteriorate even further with the predicted national shortfall of GPs.

"It is a worrying trend. It can be a last-minute appointment that keeps the service afloat, especially at weekends," Dr Simon Abrams, a GP in Everton and chair of Urgent Health UK – the representative group for out-of-hours GP providers, told Pulse. "Erosion of these services not only raises clinical risk in the community but adds to pressure on A&E".

Professor Helen Stokes-Lampard, Chair of the Royal College of GPs, said the findings were "very concerning".

"It hammers home how important it is for the government to make good on its promise to deliver 5,000 more extra GPs by 2020. More must also be done to address the serious barriers that serve to make working out of hours an unattractive option for GPs - it isn't just the unsociable hours, but the indemnity costs to work out of hours simply make it unviable in many cases. NHS England's winter indemnity scheme should help with rising costs, but they were already high in the first place."

"Better integration between routine general practice services, and GP out of hours services, is also necessary so that we can work together to ensure proper cover – and so our patients know where to turn when they are sick," she stressed.