Antipollution fault ?

my car keeps jerking, when i move it first thing in the morning. I basically have to warm it up for about 5 mins, before i can move or accelerate in the morning, otherwise it will just switch off. sometimes even when driving and i press the accelerator, it just doesnt move, however flat i press it. it has almost caused accidents at several times. Lets not even talk about the engine switching off while i'm in motion.
Took the car to 4 different mechanics at different times, and they all claimed its the fuel pump, paid them and lo and behold, it didnt solve anything. the car wasnt any better. Instead i tried to start it this morning, and the battery was dead. had to jumpstart it
its quite frustrating.
Please help anybody. its a 2003 Peugeot 307(manual transmission)