Well it’s cheaper than a brief! During my absence due to my hit and run my company employed someone to do my job. Now I’m back it turns out he was promised my job (by my manager!) and they are trying to get me to take on an entirely different role. What are my options? Can I stand my ground and demand they re-instate me in my old role or do I really have no option other than to suck it up? The other role is a lot more physical than my previous one and not too sure how the shoulder will fare at this stage! Just asking as I have no idea of employment law whatsoever. Many thanks. 
Unfortunately Vern I don’t start studying employment law til September so don’t have any particular knowledge on this area of law off-hand or any of the text books to look it up. (though just this sort of thing is one of the reasons I choose Employment Law to study)
It does sound a bit iffy to me, if you are off sick you should be able to return to your employment.
I will try and do some research, but without the basic texts and educational pointers, it is a little like flailing in the dark. Hopefully someone else will be able to answer while I flail around on the internet…hey gets me out of doing the washing up…
How long was the sickness btw? Seems to be important.
I will PM you
A quick cursory look seems to suggest that there is no statutory provisions (ie Law) that give you the right to be off sick or the right to return to work after an absence, however, it is generally covered by your contract of employment, ie you are contracted to do a job and to break that contract your employer must give reasonable grounds, so is covered by unfair dismissal regulations. So if it came to them saying, take the new job or piss off, that may amount to an unfair dismissal, as long as your contract was solid enough.
It would therefore depend rather a lot on what your employment contract states, if you are contracted to do a job, then that is the job you have a contract with the company to perform. It is very complex, from what I have been able to read it will depend on many factors that are unknown, type of contract, length of absence, number of recent absences etc etc. It might be best to talk to T.C. through PMs and give out that type of specific information, he will also know exactly what to ask for.
There is one thing that may fit the case that you present and that is Disability Discrimination law, which states that you cannot treat someone with a disability less favourably and that reasonable adjustments must be made.
It appears that your firm is trying to get you to do a job that is more physical than your current job, and that you may have a disability (your shoulder injury) if it is long-term and effects your normal day-to-day activities, long-term is classed as anything that may last 12 months or more. I have no idea of your condition so not sure if this would apply.
If it does apply, then you could reasonably suggest to your firm that an attempt to get you to do a more physically demanding job would amount to a failure to make reasonable adjustments and may amount to disability discrimination against you in breach of the statutory provisions that exist.
Long winded and vague isn’t it, but it is a complex area and there is a distinct lack of the vital information required.
Many thanks to all for taking the time to reply, had a meeting today that kind of sorted things but we shall see what next week brings.