2000 Volvo V40 Starting

The engine will not start (turn over) using the key. The battery is fully charged all dash lights come on as usual. The starter switch works as normal but the engine will not turn over.
I can activate the starter & turn over the engine by using a jumper at the solenoid terminals. There are 12 volts at the starter switch connection on the steering column. I have switched the starter relay. This came on all of a sudden. Thank you.