Peugeot 307 car wont start at all

i have mint hdi peugeot which used to be a good runner for up to 150 000 miles. After 150k it started to give me some starting problems, a hard starting so to speak. Sadly this has developed into not starting at all.Starter cranks normally but no response. Surprisingly if i put quick start or give it a slight push it runs and revs quite well as if there is no problem with it.I have checked my fuel system from the tank to the injector common rail.It appears as if the pressure from tank pump is more than that from the high pressure pump. is that normal? Please help........