UPDATE: Huge tailbacks as main town centre road blocked

Police are currently directing traffic in both directions along the Worthing Road due to an incident outside Prewetts Mill.

An officer at the scene said a vehicle had broken down and police were stopping traffic to avoid a collision.

Original reports suggested the road had been closed and that drivers were being stopped from leaving Sainsburys supermarket.

Both the road and the exit to the store remain open but traffic is queuing in all directions with some motorists stuck as far back as the John Lewis superstore and Horsham Bus Station.

More to follow.