From his intro fred I would think it is a 200Tdi. Can only guess electrical fault is cutting power to the stop solenoid. Don't think there is much other engine electrics on them.
Thanks for your reply i will remove casing and take a look .....how would thst explain it happening when putting it in reverse or applying brakes ? It do not cut out when the lights or horn and heater are used
pull the fuse out for anything that is making it cut out until it stops happening then put them back in one by one until you find out which is the problem, at least then you might still be able to use the vehicle whilst you look for the short.
Damaged wire somewhere on those circuits or could even be a faulty bulb or light unit. Take them off and clean them all up with contact spray and then try what rasher said with the fuses.