  We consider a parity-preserving QED_3 model with spontaneous breaking of the
gauge symmetry as a framework for the evaluation of the electron-electron
interaction potential underlying high-T_c superconductivity. The fact that the
resulting potential, -C_s K_{0}(Mr), is non-confining and ``weak'' (in the
sense of Kato) strongly suggests the mechanism of pair-condensation. This
potential, compatible with an s-wave order parameter, is then applied to the
Schr\"odinger equation for the sake of numerical calculations, thereby
enforcing the existence of bound states. The results worked out by means of our
theoretical framework are checked by considering a number of phenomenological
data extracted from different copper oxide superconductors. The agreement may
motivate a deeper analysis of our model viewing an application to quasi-planar
cuprate superconductors. The data analyzed here suggest an energy scale of 1-10
meV for the breaking of the U(1)-symmetry.
