How can I fix my Indesit wg1285w?

Model Indesit wg1285w. When I set the washer going it fills up but the drum doesn't turn and it won't spin at the end of a cycle. The timer seems to run through it's programme ie. pumping out water at set times. I have checked the drive belt, this is fine. Can anybody suggest which part is likely to be the culprit for this fault. I am not sure whether this is a timer fault, switch fault or possibly motor??