I'm no expert on this but as far as I was aware because my "illness" is completely "work related", if that particular work I'm doing is the thing that is making me "ill" & I am covered by the mental health/disability act then they have to at least attempt to find me alternative work. They have stated clearly that that is not possible, when it is.
They have previously twisted wording of an Occ. Health referral to say that according that doctor I am not fit for any kind of work so finding alternative employment would not be an option, this was during a meeting at which they set a date for me to return to my original job

So I'm not fit to do a different job, but I am fit to do my original one???
My step-dad used to work for the post office who had a heavy militant union & he regularly dealt with sacking people, he reckons they're fucked if they sack me & I take them to an industrial tribunal.