Electrical problem
1999 Other Peugeot Models Front Wheel Drive Manual 140000 miles

I have a peugeot 306 2.0L HDi and it wont start I thought it was diesel put £15 in it wont go tried to jump start , tow start ans free wheel start but to no avail called the RAC and he failed too, was told it may be the in tank lifter pump I can normally hear this working when I turn key to second click my mechanic mate told me the pump is working cos he took the back seat out and he could hear it working changed the heater plugs put it overnight on trickle charge in the morning it started ran for 2 mins then stopped again and would not re-start the car had been standing in very cold conditions for 2 days I would like to add please can anyone help me as Iam at a dead end.