I have some more clues to my ongoing saga;
My car dies whilst coming to a stop or even at very low speeds (such as a traffic queue) If my car dies or if I turn it off whilst in Drive or Neutral, the car will not restart for 2 minutes. The engine cranks fine however. If I turn it off from the Park position I have no problem.
I have deactivated the alarm / immobiliser using the key in the glove compartment. I have replaced the fuel pump relays.
Any ideas from detectives out there welcomed. Thanks for all the ideas so far