Patients could be asked to pay for their own crutches, walking sticks and neck braces under proposals drawn up by an NHS organisation to introduce charges for services that are currently free.

GPs in south Warwickshire have sparked controversy by examining how patients who are disabled or recovering from an accident or operation could be asked to contribute towards the cost of devices that are vital to their mobility.

Critics said the proposals were "the thin end of the wedge" and could lead to patients being charged to access core NHS services, hitting disabled and poorer people hardest.

If implemented, the proposals from the GP-led NHS South Warwickshire clinical commissioning group (CCG) could also affect patients suffering from whiplash, a hernia or sore hip or knee, or who have fractured their spine or who need help getting out of bed.

Although many patients in England already pay for dental treatment, prescriptions, glasses and hearing aids, all basic NHS services are free. Ministers and NHS England have made clear that they are opposed to new charges for care.

Sue Lear, a "service design and innovation" official working on behalf of the CCG, told its patient and public participation group last week that it was keen to reduce its annual £421,000 bill for devices that are known generically as orthotics. Its overall annual budget is £304m and it commissions and funds treatment for the 270,000 people within its borders.

Her presentation to about 20 elected patient representatives from different GP surgeries in the area posed questions about the viability of introducing charges. "Would it be reasonable to ask people to contribute to the cost of orthotics, aids and appliances? If so, which items and how could we agree this? If so, what criteria should be applied, eg low-cost items below a specified threshold?"

Lear also listed 15 different types of aids or devices to which charges, or contributions from patients, might be applied. They were: ankle foot orthoses, ie foot drop splints; wrist splints; trusses, eg for hernias; spinal supports; knee braces; hip braces; lumbar/sacral/abdominal supports; spinal support, eg for fractures; cervical support – collars; helmets; toilet aids & equipment; perching stools; walking aids – walking sticks, crutches, frames; bed mobility aids – sticks, beds, grab handles; and bath seats.

Many such pieces of equipment are never returned by patients once they have finished with them and so cannot be reused, increasing costs at a time when money is tight, Lear said. However, patient representatives told her that charges would deter some who needed such devices from obtaining them and that any means-testing would prove very complicated to administer.

The move, uncovered by the anti-cuts group False Economy, is thought to be the first time that any provider of NHS care has looked seriously into introducing charges. Two recent reports from the Reform and King's Fund thinktanks advocating charging for GP visits and hospital appointments or a £10 monthly fee to help the NHS cope with increasing demand for healthcare have prompted a debate about whether the NHS should abandon the key principle that it is free at the point of use.

Those present at the meeting said the proposal, which Lear described as "tentative", was given a hostile reception. The CCG wanted to gauge reaction to the possibility of introducing what she called "self-funding for orthotics", which suggests that it may expect at least some patients to pay the full cost of their device.

NHS England criticised the CCG's proposal. "NHS services are free of charge, except in limited circumstances sanctioned by parliament. An approach like this would appear not to meet these criteria", a spokesman said.

Frances O'Grady, the TUC general secretary, said: "The idea of charging for the use of essential items like mobility aids and braces runs contrary to everything the NHS stands for. What started out as an idea floating around rightwing thinktanks is now raising its head in clinical commissioning groups within the heart of the NHS."

Christina McAnea, head of health at the union Unison, said: "Charging patients for essential items such as crutches is the thin end of the wedge. Where do we go from here?".

Liz Sayce, chief executive of Disability Rights UK, said: "Charging for essential equipment is counter-productive and unfair and will also jeopardise independence by putting some people off getting essential equipment. And public funding is supposed legally to support proactive steps to achieve greater equality for disabled people. This would do the opposite."

The British Medical Association, the doctors' union, also criticised the move. "The NHS is facing a tough economic climate, but charging patients for important medical equipment is completely the wrong way to tackle the health service's financial challenges", said Dr Chaand Nagpaul, chair of its GP committee.

"If walking sticks, knee braces or other items are issued to patients it is because there is a clear clinical need for them. They can significantly reduce pain and improve a patient's wellbeing. By attaching a charge to these items, we run the risk that vulnerable people, especially the growing numbers of people over 70, and those in low incomes, will not be able to afford them. It could also deter all patients from seeking care," he said.

"In the long term, this measure will actually end up costing the NHS more money as patients without medical equipment will invariably have to go to their GP or visit the hospital more often because of pain, reduced mobility or suffering falls."

The CCG refused to answer questions about what it called a "very early-stage" proposal, including who had come up with the idea. In a statement it stressed its need to save money.

"NHS South Warwickshire CCG is committed to the NHS's key principle of free at the point of use. At our latest patient and public participation group, one of our discussions was about how to improve quality and value for money of our orthotics service," a spokeswoman said.

"A number of avenues were discussed, in particular helpful comments about the equipment returns process and whether charging for equipment should be considered. This has not been discussed further within the CCG since the meeting and no proposals exist to develop this further."