Anne,
I think Jackie has covered all the issues very thoroughly .
It is also good to remember that even though there is the Equality Act to use when you have illness and disability issues , that in certain cases it is REASONABLE for an employer to dismiss someone due to ill health.
The test is normally whether it is reasonable for one employer to take such action.
Any Disciplinary process should be done according to ACAS guidelines, otherwise the company can be taken to an Employment Tribunal.
Definitley get face to face advice , and if you are not legally aidable then check your House insurance to see if you have legal cover on the policy , as this can normally be used.
Medical retirement is an option only open to a few so have a look into whether that is an option.
As Jackie states ... do not resign .
The letter should have said you can have a work colleague or a Union rep with you . If you would like any one else to go with you then it is up to the company.
The reason i say to get advice is that the company could make an offer that would be legally binding .There might be an option of medical retirement but that would depend on a company pension and any clauses therein.
There used to be an Employment guy on here , so try giving the NRAS helpline a ring .
Also give
ACAS a ring as they may be able to give you some advice.
All the best
Rich :)
"The difference between 'involvement' and 'commitment' is like an eggs-and-ham breakfast: the chicken was 'involved' - the pig was 'committed'."