So I'm down at the car now. Disconnected and reconnected the battery and hooked up jump leads. Tried one of the skreem fixes I saw and held both buttons in on the key. It fired but cut out pretty much straight away. I'm now sat in it connected to another car with the dash lights on to see if I can get it to start and stay started. Hope I don't fry the ecu like I've heard others talk about!