Only one in three people who visit a GP surgery are ill enough to need to see a doctor and many of the remainder could talk to a practice nurse instead, a report claims.

Letting nurses deal with more ailments could free up enough GP time to allow them to offer patients appointments lasting up to 20 minutes, it concludes.

Reform, a right-of-centre thinktank, claims the change would relieve the serious strain on GPs, reduce the number of people going to A&E and save the NHS £700m a year.

GPs currently deal with two-thirds of the 372 million appointments a year in England, and nurses the other third. But nurses and other health professionals could safely take on about half of doctors’ current workloads, Reform argues.

Nurses could see patients with minor illnesses or injuries, leaving GPs to see one in three cases. If nurses were to handle the 57m consultations a year involving minor ailments the NHS would save more than £700m a year, the report claims.

But the Royal College of GPs said shortages of nurses meant such a shake-up could not happen. “Relying more on practice nurses is impossible when many surgeries are struggling to recruit, and existing practice nurses aren’t simply sitting around waiting for patients to walk through the door. They are under just as much pressure as GPs,” said Dr Maureen Baker, the RCGP chair.

With just 7% of GP appointments booked online, the report criticises GPs for not using technology nearly enough to make patients’ and their own lives easier. It advises that greater use of video consultations, using smartphones or computers, could allow GPs to deal with more patients more quickly.

Baker said GPs were increasingly offering appointments that did not involve face-to-face contact, such as telephone consultations. “But despite our efforts, demand is rising so acutely that this is having little effect in terms of our workload.”

Research in the Lancet medical journal last week found that GP workloads in England grew by 16% between 2007 and 2014 and that surgeries were now so busy that they were approaching “saturation point”.

Reform also claims small GP surgeries are out of date and that much bigger “super practices”, potentially covering as many as a million patients, are the future of general practice.

A typical GP surgery has about 7,500 patients. However, much larger practices – such as Lakeside Healthcare in Northamptonshire, which has 100,000 patients and aims to treble that – provide a much wider range of services, it says. Super practices provide better care, Reform argues.

The RCGP disputed Reform’s claim that enough patients wanted to see a GP at the weekend to justify such schemes. Some weekend-opening initiatives designed to pave the way for the government’s pledge to introduce seven-day GP access were scaled back recently because too few patients turned up.

Reform says patients in Herefordshire have taken up 80% of the available weekend appointments now that there is greater awareness of the extended opening hours.