  We study the SU(2) gauge theory with the interpolating gauge {\it a la}
Parrinello--Jona-Lasinio--Zwanziger (PJLZ) with the gauge fixing functional
$F=\sum_{x\mu} {1/2}\tr (U_{x\mu}\sigma_3U_{x\mu}^{\dagger}\sigma_3)$. We find
a strong indication of the non--analiticity with respect to the interpolating
parameter $\lambda$ at $\lambda_c \sim 0.8$.
