One in five patients now has to wait at least 15 days to see a GP in England, NHS figures have revealed.

Just under 5m of the 27.1m appointments at GPs’ surgeries in October involved waiting anywhere between 15 and 28 or more days to see a doctor or practice nurse. That was almost one in five (18.3%) of the total consultations available, NHS Digital figures showed.

The publication of the figures – the first of their kind ever issued by the NHS – have prompted renewed concern about how the rising demand for care and shortage of GPs are forcing patients to wait much longer than before for an appointment.

GPs’ leaders highlighted that 40% of people got to see a doctor or nurse on the day they called. Another 6.6% were seen within 24 hours and 20.3% within between two and seven days. Taken together that meant that two-thirds (67.1%) of patients got an appointment inside a week.

However, the figures showed that just under 4 million people – one in seven (14.5%) – faced delays of between eight and 14 days, another 2.2 million (8%) waited 15 to 21 days and a further 1.4 million (5.3%) between 22 and 28 days.

Another 1.37 million (5%) waited over 28 days, according to the statistics, which were based on data returns from 6,354 GP practices across England, 90% of the total.

The leader of Britain’s GPs said the growing delays were frustrating for family doctors as well as patients and warned that they could lead to some people’s illnesses getting worse.

“Despite the best efforts of GPs and our teams, who are working incredibly hard to deliver more consultations than ever before, our patients are waiting too long to secure a GP appointment. We know this is frustrating for them and their families, and it’s frustrating for GPs and our teams too,” said Prof Helen Stokes-Lampard, the chair of the Royal College of GPs.

The government pledged in 2015 to increase the number of GPs in England by 5,000 by 2020. But numbers have actually fallen by 1,000 since then.

“We want to deliver timely care to patients in the early stages of illness to avoid conditions getting worse, when they can be both more distressing for patients, and more costly for the NHS.

“It’s encouraging and a great testament to the hard work and dedication of GPs that more than 40% of GP appointments are made on the same day the patient is seen, so we are confident most of those who are acutely unwell are being provided for,” added Stokes-Lampard.