have you just changed your fuel filter and now it does'nt start or has it
just happened?
is it a common rail?
are you sure its just not a air lock?

if you havent just done anything to it then
disconnect the fuel return to the tank and crank it over - with the return
pipe going into a clear bottle. now carefully look at the diesel thats in
the bottle - what your looking for is any swarf/metal particals mixed in
the diesel this means that the pump is breaking up inside (smell it and
check for a petrol mix)
(ive known petrol tankers to put into the wrong pump)

note; if you do need a new fuel pump it will have to be proggrammed for
the PATS immobilser