Data from 393 practices represented by accountancy firm Ramsay Brown and Partners show that 76 - almost 20% - have levels of profit per partner below the cost of employing a salaried GP for eight sessions per week.
Practices in this situation have been dubbed 'zombie practices' - a term borrowed from the business world, in which zombie companies is a description given to those able to limp along paying their bills, but struggling to make any significant profit or bring down any debts they may have.
Nationally, the data suggest that around 1,500 practices could have partners earning less than salaried doctors. But the true number of GP practices across the country in this position could be significantly higher - because the Ramsay Brown practices tend to report levels of profit per partner above the national average.
The figures also fit with data reported in the BMJ for Cambridgeshire, which quoted the managing partner of a superpractice as saying that a fifth of practices in the county are 'zombies'.
GPC deputy chair Dr Richard Vautrey told GPonline that the rising cost of employing salaried and locum doctors was forcing many partners to take on more work to stop their practices going under.
'GP partners are working longer and longer hours to try and keep their service going, but this is not sustainable and leads to GPs making themselves ill and burning out,' he warned.
GPs have repeatedly called for a cap on the number of consultations each GP can take on per day, and GPonline reported earlier this year that practices across England deliver 1m appointments per week above the level considered safe by the BMA.
Laurence Slavin, a partner at Ramsay Brown, told GPonline that if the supply of available doctors to fill vacancies did not increase, the rising cost of hiring salaried doctors 'might be the factor that makes some practices decide to give up their contracts'.
'The problem is just one of supply and demand,' he said. 'If practices are squeezed, they will let salaried and locum GPs go.
Supply and demand
'Partners are taking on bigger burdens, or just saying we can’t offer appointments. Practices are starting to ration - saying that they just don’t have the resources to offer appointments [to every patient who wants one].
'The government or DH don’t understand how much harder GPs are working than a few years ago - they see static profits because GPs are working harder, longer hours and taking on more work.'
The basic cost of hiring a salaried GP is around £10,000 per session per year, Mr Slavin said. With 'on costs' this comes to around £12,800, equivalent to £102,400 per year based on eight sessions a week.
This is slightly higher than the latest national average figure for profit per partner quoted by NHS Digital, and more than partners' profit share at 76 of the 393 practices for which Ramsay Brown provided data.
Dr Vautrey warned that practices struggling to recruit also faced significant costs if they were forced to rely heavily on locums.
'We can't have practices just using locums - it has an impact on continuity and cost. We have had some practices close where they were completely unable to recruit and have had to rely in the short-term on locums, which is not sustainable.'
Dr Vautrey said that although there had been 'small rises in overall income for partners' in recent years, these had been eroded by inflation in real terms. 'Doctors are significantly behind where they should be if the government had been funding general practice and pay rises in line with inflation,' he said.
It's no wonder practices have reached the point where some are no longer viable and doctors are choosing to quit instead.'