i had a vrs and as already suggested blocked up oil pick up strainer is very common on these.
i would not be driving it or starting it until the oil light issue is resolved,hopefully it is the sensor but it could well be a blocked strainer.
its a cheap and easy fix as long as you have not run it with oil not getting round the engine.
if the sensor does fix the fault and you plan on keeping the car i would get the pick up pipe changed anyway.
also coolant temp sensor, water pump,thermostat and cam belt failures,all common faults.