Starting from known physical balance laws and constitutive equations, this work develops in a rational number the canonical balance laws of momentum and energy at both regular and singular material points. This is achieved in the framework of the quasi-electrostatics of thermoelectroelastic crystals, with a view to providing a sound basis for the study of electroelastic fracture, and of the propagation of phase transition fronts. The latter receive special attention with the formulation of a true thermomechanics in which it is shown that a hot surface heat source develops at thermodynamically irreversible points of progress of such fronts. The expression of the driving force acting on such fronts in these conditions is obtained in terms of the relevant Hugoniot-Gibbs functional. This provides the basis for the formulation of simple criteria of progress of the front.