A total of 80% of 522 GPs who responded to a GPonline question about superhubs said they believed shifting services into these larger units serving around 40,000 patients would undermine general practice.
Just 5% said the move would improve GP services, while 3% said it would have no impact and 12% were unsure.
More than half of GPs (52%) said they would not be prepared to work in a superhub model, while among 265 GP partners responding to the poll, 57% said they would not be prepared to move their practice into a superhub.
Just 19% of partners said they would be prepared to make the switch, while 24% were unsure.
The findings come just a week after health minister David Mowat told MPs in the House of Commons that the NHS was finding across England that 'it's working better by putting GP practices into hubs of 35,000 to 40,000 people'.
He told MPs last week: 'We’re migrating over a period of time to a position in which – there are 7,500 GP practices around the country – to something more like 1,500 of these super hubs. But the contract position hasn’t caught up with that, and that’s a long road.'
Many respondents to the GPonline poll cited concerns that shifting to at-scale GP models would undermine continuity of care, valued in particular by rising numbers of patients with long-term conditions. Recent research has confirmed that continuity of care is a key factor in reducing hospital admissions among older patients.
GPs also warned of fears that centralising services would force patients to make longer journeys - particularly in rural areas - and undermine the strengths of small GP practice teams.
Continuity of care
One GP respondent said: 'We are a relatively large practice serving approx 12,000 patients - I think that there is a maximum number of patients that can be served well and I really do believe that "relatively small is beautiful".
'I think if very large superhubs come in it will depersonalise the service - it may suit the young patient but for the older population with chronic diseases I think they will get a worse deal and I think it will destroy any continuity that we now cling onto.'
A GP in Greater Manchester wrote: 'Patients have a strong desire to see a regular local GP. I am one of only two full-time equivalent GPs at the practice and patients delight in having easier access to continuity if care.
'They also value seeing somebody within close reach (especially the elderly). Superhubs would depersonalise care and lead to poorer concordance from patients, resulting in poorer general health.'
A salaried GP responding to the poll said: 'Just come from practice with 26,000 patients, no continuity. It's not general practice, it's a combination of out-of-hours emergencies and hospital outpatients with no previous knowledge of complicated patients.
'Try doing an appropriate medication review of a patient who you have never met before on 24 conflicting meds from chronic diseases in 10 minutes! If you know the person, can do it over time.'
Another GP warned: 'It is the proximity and familiarity of their GP which is most valued [by patients].This scheme will remove the patient-centred care model and will definitely herald the demise of family practice as we know it today.'
One GP said Mr Mowat's superhub plan was 'taking economies of scale to a level that undermines the fundamentals of general practice'.
Some respondents acknowledged that pressures on general practice from rising workload, underfunding and bureaucracy - in particular from 'pedantic and extensive' CQC inspections and QOF box-ticking - were so great that some practices felt they had no choice but to work at scale.
The DH has said it is not planning to shut practices down in the move to create superhubs, but sustainability and transformation plans (STPs) in parts of England have set out proposals to significantly reduce numbers of practices to co-locate services in larger hubs.