Lotus Elise S1 won't start.. fuel pump problem?

[s1elisedriver]

Hi all i am from Sydney Australia and have a s1 elise, and am experiencing the same problem Fuel Pump not priming. It happened when i was stuck in traffic one hot sunny day and the car just stopped on me, after several attempts trying to start eventually got it towed to a garage, the mechanic showed me the fuel filter was full of dirt and looked brown, he has checked fuses and the multi function relay unit appears to be fine, he assumes tank would be filled with this dirty dead fuel thus causing the fuel pump not to work, also the fuel cut off switch seems to be removed i cant find the damn thing anywhere. so im guessing its the fuel pump itself, i was just curious every time it happens it happens on a real hot day, why is this? has it got do to with the fuel heating up..? the car getting hot? the car has not ever overheated, so buggered if i know