Trouble is there are so many variable's,such as contract, medical declarations, nature of work, nature of illness... each individual case is different so you can't extrapolate from Bagpuss' case to cover all similar presentations.As a rule of thumb only, if you have declared a disability or acquire a disability in a work environment, your employers must make such adjustments as are reasonable for you to continue in your job.Further, if you have been refused a job, or demoted due to disability you can sue.