Health officials are to launch a review into the closures of NHS walk-in centres.
Regulator Monitor said that it will assess whether the closures are “in the best interests of patients”.
Labour estimates that as many as 40 of the centres, which treat patients with minor illnesses and injuries without them having to make an appointment, have closed since the coalition government took office.
Experts plan to examine whether the closure of such centres have limited patients’ ability to choose where and when they access care when they do not have an appointment.
The crisis in emergency services has in part been attributed to the closure of such centres.
Catherine Davies, executive director of co-operation and competition at Monitor, said: “It is in the interests of patients to find out why walk-in centres are closing and whether the closures are affecting patient choice and competition.
“Walk-in centres are very popular with patients and the potential impact of such closures at a local and national level needs to be better understood.”
According to the NHS Choices website, the walk-in centres “have proved to be a successful complementary service to traditional GP and A&E services”.
Some of the high profile closures in recent years include two London-based centres in Tooting and Victoria.
Labour’s shadow health secretary Andy Burnham said: “I welcome that intervention by Monitor.
“We have been saying for some time that it is a false economy to close walk in centres. They have helped take pressure off A&E departments and it makes no sense that so many have been closed in the last two or three years.
“We have estimated that about 40 have been closed since the Coalition came to power.”
On Thursday Labour held an “emergency A&E summit” so that medics and health experts could come together to talk about the emergency care crisis.
It emerged that private ambulances are responding to as many as half of 999 call outs in some parts of the country.
Stretched NHS ambulance staff are having to rely on counterparts from the private sector to handle as many as 50% of call outs, according to Leeds paramedic Debbie Wilkinson.
Ms Wilkinson, who is also chair of the union Unite’s national ambulance committee, described the pace of the increase in the use of private ambulances as “insane”.
She said that patients and their families do not know exactly who is turning up on their doorstep, adding: “We can’t guarantee who is turning up on your door is exactly who should be. So really it becomes a postcode lottery when you ring 999.”
A Department of Health spokeswoman said: “From 1 April 2011, a new system of regulation began for the independent ambulance sector. Independent ambulance services now need to register with the Care Quality Commission and meet the same essential standards of quality and safety that NHS ambulances do.”
During the summit, Mr Burnham called on the government to plough the money which the NHS “under spent” last year into local councils so they can provide better social care.
“Last year there was an under spend in the NHS of around £2 billion we are saying that the government should return around half of that to the Department of Health to take pressure off social care over the next two years,” he said.
“The collapse of social care in England is one of the principle reasons why the system is under such intense pressure and we want the government to take that matter more seriously.”
Experts have recently said that emergency care systems could collapse in six months as a result of rising demand.
Mr Burnham added: “We are aware that everybody is under pressure at the moment at every level of the system. It is not just hospitals, it is general practice, its social care provision, community services.
“The government have spent the last few weeks picking a fight with GPs and in doing so have lost precious time. They failed to face up to the fundamental causes of the pressures on A&E it is now imperative that they do so and develop a practical plan to take the pressure off hard-pressed staff.”
Officials at NHS England are also examining the way urgent and emergency care is provided.
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