  We prove a restriction type estimate for sub-Laplacians on arbitrary two-step
stratified Lie groups. Despite being slightly weaker than previously known
estimates for the subclass of Heisenberg type groups, these estimates
surprisingly turn out to be sufficient to prove an $L^p$-spectral multiplier
theorem with sharp regularity condition $s>d\left|1/p-1/2\right|$ for
sub-Laplacians on M\'etivier groups.
