Hi I have a 2003 2.0 crd diesel and have a strange problem !

If I use the car daily it starts fine if I leave it longer it just turns over and wont start (the battery eventually goes flat).
It eventually starts with a jump from another car.
I have replaced the battery .

There seems to be a slight diesel leak above the gearbox under the engine cover (it also smells of diesel under the bonnet)

Thanks for your advice in advance

 

Do you think it could be the hp fuel pump ?

Someone said it is located on the end of the head above the gear box.