Some years ago I changed my GP. I did not offer him an explanation, nor did he ask for one. He did not complain to the local family practitioner committee, nor did he write indignantly to the health service commissioner. I do not imagine for a moment that the GP ever expected to receive an explanation.

When the boot is on the other foot, however, it seems patients do want to be told why they have been removed from their GP's list. The health service commissioner says that GPs should explain and the British Medical Association agrees with him. I disagree.

The statutory right of patients to change their GPs without explanation, and the reciprocal right of GPs to remove patients, goes back as far as Lloyd George's National Health Insurance Act of 1911.

Since 1911, nothing has really changed. Doctors' and patients' mutual rights to abandon one another have been clearly set out in all subsequent revisions to the GP contract. The right of GPs to remove patients without reason is now found in the NHS (General Medical Services) Regulations 1992, while patients' rights in the matter were recently reaffirmed in the NHS (Choice of Medical Practitioner) Regulations 1998.

The rights are, in fact, not quite equal. GPs must give a week's notice before removing a patient, while patients may change GPs without notice. Furthermore, GPs may not remove patients who are currently receiving treatment that requires them to be seen at intervals of less than a week, nor may they immediately remove patients who have been 'assigned' or allocated to them by a health authority.

Around 30,000 patients are removed from GPs' lists each year. But this figure should be put in context: it represents only one case per GP per year - one patient in 1,800. And every year more than

2 million people change GP without explanation.

Over the past 25 years, I have spoken with hundreds of patients who have been 'struck off' by their GPs. Many were angry, but very few didn't know why they were being asked to leave a practice.

In the vast majority of cases the reasons were so obvious as to need no explanation: there had been a significant disagreement or even an assault, which had understandably led the GP to wish to terminate the relationship.

Only in a handful of cases was the reason so mysterious that it was worth looking into further. On one - and only one - occasion, I discovered that the GP had inadvertently asked for the wrong patient to be removed; in most other cases it emerged that the patients had been less than frank.

Usually, but not always, GPs were willing to provide an explanation when asked - though they were often keen to remind me they were under no obligation to do so.

Since 1974, community health councils have raised the issue of GPs not giving explanations on many occasions and have called for changes to the statutory rules. While no direct legislative changes have so far been forthcoming, professional attitudes have changed over the years. Where once the profession's representatives would have simply issued a curt response that 'GPs have a right to remove patients - full stop', the official line has changed considerably: GPs are today advised, though still not required, to provide explanations.

The new NHS complaints procedures may already provide one avenue for ex-patients to discover the reasons for their removal. GPs are now formally obliged to have in-house complaints procedures. Having such a procedure and responding to a complaint does not, of course, guarantee that the response will satisfy the patient.

That is the crux of the issue. Would a statutory right to an explanation make any difference? Or would it raise the false expectation that if a patient didn't like the reason given, someone might do something about it?

GPs who did not wish to explain themselves but were compelled to do so would probably fall back on meaningless generalisations such as 'breakdown in doctor-patient relationship'. One reason GPs sometimes understandably do not want to provide explanations is that they have no wish to become embroiled in further conflict.

There are, however, cases where an explanation would be not just polite but also reassuring to patients, such as where a GP was simply tidying the practice's geographical boundaries.

These are rather different from those cases in which a patient might conclude that a GP has acted maliciously - for example, where a patient has fallen out with a GP, who has then asked not only for the patient but the entire family to be removed.

The root of the problem, perhaps, lies in patients' false impression that their GP is part of the NHS. But GPs are not part of the NHS. They are independent practitioners with whom patients choose to register for private treatment, which is then paid for by the NHS.

This is a very important point. Were patients conditioned to think of their relationship with GPs as being more akin to their relationship with their solicitor or hairdresser, they might feel less aggrieved should that relationship be inexplicably and unilaterally terminated

A pub landlord once refused to serve me. No explanation was offered. I didn't lobby for the legal right to be told why - I simply took my custom elsewhere. Offering explanations may be courteous, but should we really expect courtesy to be enshrined in law?