Martin. Thanks for your help. As you suggested I looked for a crank sensor. Found a sensor on the gearbox mounting (which must sense the flywheel). The connector had been previously broken and held on with insulating tape. The connector wasn't plugged right in to the sensor. Pushed it in and the car started straight away. Was a lot easier than trying to faff around with the ignition module which is at the back of the engine. Have now superglued the sensor and plug together (if the sensor needs replacing, the connector needs replacing anyway).
Thanks for your help. Much appreciated.
Andy