My mechanic reckons it's the fuel filter head. I've put him in touch with M&D so they can work it out. It's a week out of warranty - fingers crossed they are in a good mood. Any other blips I've had, they've sent bits out FOC.
Found a pic on your build thread. Lift pump looks the same as a standard one. It shouldn't have failed after 6k miles but its less than 5 minute job to swap. I didn't even have to bleed my fuel system when I did mine.