2010 V70 R Fuel Pump Issues
 

I have a 2010 V70 R-Design 2.5D and over the last couple of months have had intermittent starting issues.
Normally when I push the Start button I can hear a buzz come from the rear of the car and then the car starts. Recently though, this noise has not been heard and the car just cranks over and fails to fire.

The car was diagnosed with a faulty fuel pressure regulator which was changed along with the rail, and pressure sensor and the car started first time. 3 days later same problem came back.
Each time the problem has occurred it has been noticed that the fuel level in the car is around the halfway point and the car has been parked on a slight downward angle. Reading other posts, have managed to get the car started by adding more fuel.
I feel now though that in the in tank pump has failed as the car has not been able to start now for a week no matter what is tried.
Could anyone point me to the part number of the pump or any other ideas as to what could cause this as so far each the the car has been plugged in to a diagnostic computer it is only registering low fuel pressure.
Incidentally, the trick of knocking the fuel tank has now stopped working.

TIA