Hello my name is ***** ***** I am happy to help you today. Are all staff being asked to work these new shifts?
Are you being given notice of a change of terms and conditions?
Ok thanks what is the nature of your health concern that prevents you from working night shift?
Ok it does not seem that that is sufficient to argue that you are a disabled employee for employment law purposes unfortunately as there needs to be a recognised impairment.
In this situation unfortunately the employer is entitled to change terms from time to time, even if they are less favourable. This is particularly the case if there is a business need to do so. Provided you are given adequate notice (12 weeks) then there will be little you can do about it if you choose not to accept the new shift pattern.
The suggestions that have been made do meet the legal requirements in this area.
I realise that this is not the answer you wanted to receive and do think that you should raise a grievance on the impact of this on you and patient health and safety. I would hope that they would agree to make you an exception.
If you have any further questions please do ask. If I have answered your question I would be grateful if you would be so kind as to rate my answer. Thank you and all the best.