I injured my knee two and half weeks ago and I am due to go into hospital shortly. I have attended work on crutches during this time but last week my employers told me that I would need to get a certificate from my doctor to say I was fit for work. I duly went to the doctor who advised that he would not do this as he had not signed me off work and I hadn't been on the sick, he did however provide me with a written letter which stated that I was happy and felt healthy enough to attend work for the two and half weeks since the injury. I attended work on Friday 19th Oct to be told that if I attended work again on Monday I would be told to leave the premises due to me using crutches as they felt they were a health and safety issue to myself and my colleagues. I am an admin worker in an office and I am sat at my desk only getting up to use the facilities that I require throughout the working day. I want to know if they have the right to stop me going onto the premises, they have not given me any written documentation explaining the reasons why they will not allow me into the office and I am afraid that if I do not attend then, this will go against my sickness record and as I will be off work after the operation then this will be another mark against my sickness record.