You have been told by your treating doctor that he/she will not issue a: 'medical certificate'. In doing so, your doctor has acted in accordance with the rules laid down by the KNMG, the professional organisation for doctors. For more information, see also deze pagina van de KNMG.
The KNMG's position is that an attending physician should not issue statements about one's own patient in which he/she gives an opinion about a patient's (medical) fitness or unfitness to do or not do certain things. Examples include: is someone able to work, drive a car, go to school, take good care of the children, is a booked trip cancelled rightly, or is someone entitled to a parking permit or adapted housing?
Such certificates may only be issued by an independent doctor (i.e. not your 'own' doctor). Such a doctor can make his or her own assessment of your situation. If necessary, with your consent, that doctor may also request additional information from your treating doctor(s).
The two main reasons for this position are:
The KNMG believes it is important that the treating doctor can concentrate on your treatment and build a good relationship of trust with you. Your doctor should then not get into all kinds of conflicts of interest. To prevent this, there should be a sharp boundary between treatment and assessing whether you can qualify for certain facilities. In this way, nothing prevents you from giving your doctor all the information necessary for your treatment.
In addition, your treating doctor is often unaware of the criteria used to allocate or not allocate certain facilities. This often makes it impossible to give a proper opinion. It is also in your interest that the doctor issuing the medical certificate is well aware of which points are and are not important in the assessment.
If you declare that you are ill, the authority requesting a declaration must believe it. In principle, this should be sufficient. If the asking body does not believe you, that body must appoint an independent doctor (not a practitioner) to assess whether your story is true. The assessing doctor should then examine you (possibly only with written questions). Sometimes that assessing doctor, usually called a medical adviser, needs information from your treating doctor. The assessing doctor (i.e. not the authority) may then (with your consent) request information from your treating doctor (e.g. your GP). Only factual information may be requested.