British doctors will take the historic step of admitting for the first time that many health treatments will be rationed in the future because the NHS cannot cope with spiralling demand from patients.

In a major report that will embarrass the government, the British Medical Association will say fertility treatment, plastic surgery and operations for varicose veins and minor childhood ailments, such as glue ear, are among a long list of procedures in jeopardy.

James Johnson, the BMA chairman, will warn that patients face a bleak future because they will increasingly be denied treatments. He will urge the NHS to be much more explicit about what it can realistically afford to do and ask political leaders to engage in an open, honest debate about rationing.

The BMA proposes the drawing up of a new patients' charter specifying those health services to which every citizen across England should be entitled, regardless of the local health authority's financial situation. They also want to see a second list of all the treatments which the sick will get only if their primary care trust has the money, and if doctors decide they are clinically worthwhile.

Senior BMA sources say their report recognises the reality that despite record investment in the NHS, 'postcode lotteries' are rife. Primary care trusts, the local NHS organisations that commission and pay for care from hospitals on behalf of patients, are increasingly rejecting requests to pay for procedures or drugs because they are not perceived to be the best use of funds.

Some PCTs have been bitterly criticised for refusing to pay for expensive new cancer drugs; treatment to prevent older people going blind through age-related eye degeneration and operations to help obese patients lose weight through stomach-stapling.

Each trust already has a committee of medical experts that takes decisions on whether to fund medication for complaints which are not covered in their basic contract with the Department of Health. These include treatments such as growth hormone for adults, neuro-stimulation for migraines, breast reduction and enlargement, treatments for incontinence and even some care for multiple sclerosis.

Johnson will use the launch on Tuesday of a BMA discussion paper on the future of the NHS in England to spell out his belief that Britain's ageing population will put ever greater pressures on local NHS organisations to decide how best to use their resources, and that the public's reluctance to put significant extra funding into the NHS means rationing will become increasingly common.

Dr Michael Wilks, one of the BMA's senior office holders, revealed the organisation's radical thinking in a recent letter to its 139,000 members updating them on the progress of the BMA working group, headed by Johnson, which has drawn up the document. He told them the group had concluded that 'while the service should remain universal, the challenges raise questions about how comprehensive the service can continue to be. This will depend on whether politicians and the taxpayer are prepared to contemplate either increasing expenditure or explicit rationing.

'Rationing of health care in one form or another has always existed but has not been discussed. While agreeing that an open and honest debate on rationing is needed, the nature of that debate needs to be clarified. It might, for instance, address whether current inequities in care caused by pressures to balance the financial books are preferable to one alternative, which is to set a limit on the availability of some procedures.'

Health Minister Andy Burnham last night welcomed the report as a useful contribution to the debate about the NHS's future. He defended the NHS as 'the right model for Britain's future'.

'[It is] a system which makes the most modern treatments and medicines available and that is envied by other governments around the world as a fair and cost-effective way of providing high-quality health care to a whole population based on need alone.

'I would resist any call to make the NHS a slimmed-down, emergency service, because that's what it would become if we started saying "you can have this" and "you can't have that". It should continue to be comprehensive and universal.'