  The interplay between superconductivity and Eu$ ^{2+}$ magnetic moments in
EuFe$_2$(As$_{1-x}$P$_x$)$_2$ is studied by electrical resistivity measurements
under hydrostatic pressure on $x=0.13$ and $x=0.18$ single crystals. We can map
hydrostatic pressure to chemical pressure $x$ and show, that superconductivity
is confined to a very narrow range $0.18\leq x \leq 0.23$ in the phase diagram,
beyond which ferromagnetic (FM) Eu ordering suppresses superconductivity. The
change from antiferro- to FM Eu ordering at the latter concentration coincides
with a Lifshitz transition and the complete depression of iron magnetic order.
