Can employer force employee to take sick leave?

[FlipWreck]

Hi - NC'd for this, but I'm a regular and have had excellent advice from this board before. Please can someone answer this - can an employer force an employee onto sick leave? The employee has cancer, but has a fit note from their doctor saying they are well enough to work and undertake light duties. If the employer tells them not to come into work, can they also move them onto sick leave (which would reduce the employee's entitlement to their contractual amount of sick leave)? TIA.

Hi I have been with the company 17 years. I have been working at head office for the past 3 years on a telehandler. They put me on site around 6 months ago doing some digging. Which I pulled my back. So got a sick note for 2 weeks then a back too work note putting me on light duties. But they have told me I cant drive any plant or company vehicles as of my prescription pain killers. Oramorpine morphine. Which I have been on for 5 years and work have know about this. As I have declared it. I only take it when absolute necessary. As I had this as relief for my gaul bladder out and pancreatitis which flais up every now and again. They put me on light duties and now they said I have too go on the sick. Even though I will do anything with light duties. And the job I was in at head office thiercis work their. But my manager is blocking it for some reason.