The lunchtime demonstration took place outside a GP at Hand facility in Poplar, east London - which campaigners, who braved heavy rain to carry out the protest, say was set up alongside existing practices without any warning.
Campaigners say neighbouring practices have received angry calls from patients who signed up to GP at Hand without realising that doing so meant they would be deregistered from their existing GP.
They also warn that by attracting large numbers of younger patients, the service is stripping away funding that existing practices need to provide services for older, sicker patients. GP at Hand, meanwhile, is not open to a wide range of patients with complex needs, including those who are pregnant, have dementia or other conditions.
The Poplar surgery is one of five locations at which patients registered with the video consultation service can have face-to-face GP appointments. Patients who sign up are registered on the patient list of the Lillie Road Medical Centre, in Fulham - which has seen its list size grow from 2,500 in April 2017 to 24,652 on 1 March 2018.
Around 20,000 patients have joined since the practice opened up the GP at Hand service to out-of-area patients, and 85% of these new registrations have come from patients aged between 20 and 39.
Hammersmith and Fulham CCG has warned that the rapid expansion of the service could leave it facing increased costs of up to £10m and a deficit in 2018/19.
A CQC report last week found that almost half of private online GP providers were unsafe. A CQC inspection report on Babylon - the private online provider whose technology is behind the GP at Hand service - is among those that fed into the report on online GP services.
The report on Babylon found that 'in some areas, this service was not providing safe care in accordance with the relevant regulations', although the company has strongly criticised the findings and said 'narrow concerns' highlighted by the regulator 'do not apply to the GP at Hand service'. GP at Hand itself was rated 'good' by the CQC.
A GP at Hand spokesman said: 'People have the right to choose their NHS practice. GP at Hand is an NHS service paid for by the NHS, providing NHS services to all patients - just like the vast majority of GP practices throughout the UK.
'GP at Hand offers GP appointments within minutes via smartphone, 24 hours-a-day, seven days-a-week, 365 days-a-year. Since its launch in November 2017, the service has attracted over 26,000 members and received over 8,700 5-star ratings for our digital appointments.'
Tower Hamlets LMC chair Dr Jackie Applebee said: 'Surgeries like my own are now getting lots of calls from angry former patients, who didn’t realise that by using GP at Hand they were deregistering from their usual surgery. Some are insisting on reregistering, causing a lot of extra work for our staff.'
She criticised GP at Hand's restrictions on complex patients. 'We think that’s because these patients are expensive. This service takes money from the NHS, by picking the most profitable patients.
'Sick patients inevitably use more of the available funding and resources, but the system [for traditional GP practices] is fair because we all eventually end up in the group that’s sick.
'But now that thousands of young Londoners are signing up with GP at Hand, they are taking NHS money away from GP surgeries who need it to take care of the old and sick. This is bad news for everyone – except GP at Hand.'
An NHS England London spokeswoman said: 'Hammersmith and Fulham CCG, where the GP at Hand practice is based, undertook a clinical review with NHS England in October 2017. This assessed governance, safeguarding, and risk management, among other areas. A number of recommended actions were made in the report, which have been completed or are underway.
'We are committed to working with patients, the GP at Hand practice and the local CCG to ensure that patient care is not compromised and that GP at Hand provides a safe, effective service as part of the wider health and social care system.'