  We present a detailed analysis, in the framework of the MFA approach, of the
critical behaviour of the lattice Schwinger model with Wilson fermions on
lattices up to $24^2$, through the study of the Lee-Yang zeros and the specific
heat. We find compelling evidence for a critical line ending at $\kappa = 0.25$
at large $\beta$. Finite size scaling analysis on lattices $8^2,12^2,16^2,
20^2$ and $24^2$ indicates a continuous transition. The hyperscaling relation
is verified in the explored $\beta$ region.
