Doctors and patients' groups have criticised proposals by health minister Lord Darzi to reorganise the GP system in England.
Lord Darzi wants to replace surgeries manned by a single GP with larger "polyclinics", which are run by several doctors and offer specialist services.
The government has suggested the policy would only apply to bigger GP clinics.
But the British Medical Association says they will be wasteful and will undermine continuity of patient care.
Speaking to the BBC Breakfast programme, Lord Darzi said single-doctor clinics belonged in the past and warned that although "most patients love their GP", a change was coming.
He believes polyclinics, which house GPs alongside medical services normally offered at hospitals, are better suited to patients' needs.
Lord Darzi praised the "fantastic" relationship between doctors and their patients, but said it must be distinguished from modern practices, where there were now often several GPs working under the same roof.
He said: "I have no doubt in the future we are going to see a critical mass of general practitioners working together, rather than what we used to see in the past which were practices with a single-handed clinician."
Ministers have already said they want to establish 150 polyclinics across England.
But Richard Vautrey, deputy chairman of the British Medical Association's GP committee, accused the government of trying to impose a "London-centric" model on the whole country, when it was inappropriate for less populated areas.
He said: "This is a government plan that is potentially going to waste hundreds of millions of pounds of scarce NHS resources, creating very large health centres that many areas of the country simply don't need or want."
He also warned the government's proposals could bring competition for NHS work from large multinational private companies.
"They are effectively going to be looking for the cheapest bidder, who is going to run these health centres," he added.
Shadow health secretary Andrew Lansley said Lord Darzi's proposals would not appeal to most people.
"He's talking about 25 GPs in each of his polyclinics, serving a population of 50,000," he said.
"I think most people in most parts of the country would be perfectly happy with a GP surgery which has, typically, two or three principals, perhaps up to six or seven."
Cradle to grave
Dr Anthony Halperin, chairman of the Patients Association, said he was not convinced by the idea of GPs and specialists working under the one roof.
"What I believe patients want is to see their own GP, to have a regular relationship with a GP, and when they require further or more specialist treatment to go to a hospital," he said.
"What you are now doing is interposing a third layer of a polyclinic and I really don't see any advantage for it."
Peter Weaving, a GP in Brampton, near Carlisle, said being a general practitioner in the UK and being able to treat generations of the same family was a "wonderful thing".
"I have been in practice for nearly 25 years," he said. "I have looked after patients from when they were babies to when they've grown up, and they've brought their babies to me.
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"It's very important that whatever developments modern medicine brings, we don't lose that underlying personal relationship."
Professor Steve Field, from the Royal College of General Practitioners, told the BBC the organisation was not against the principle of polyclinics as long as the doctor-patient relationship was preserved.
He said: "What we're really adamant about is that continuity of care you get in general practice, which really makes general practice in the UK the best in the world.
"And what we mustn't do is undo what's great."
Public Health Minister Dawn Primarolo suggested the policy would only apply to those larger practices that were already starting to function like polyclinics.
"It's very important that you have access, that you are reassured you have a good... understanding with your GP, and none of that is going to change," she said.
"And in big centres those services can be broader, but obviously in smaller communities you need still to have the access, and that means the provision may be built around individual or one or two GPs."
Lord Darzi has been commissioned by Prime Minister Gordon Brown to carry out a wholesale review of the NHS in England, and polyclinics were a high profile feature of his interim report published last year.
It is understood his final report will be published this summer.
He also proposed the introduction of polyclinics in his 2007 review of the NHS in London.