  We consider an interface above an attractive hard wall in the complete
wetting regime, and submitted to the action of an external increasing, convex
potential, and study its delocalization as the intensity of this potential
vanishes. Our main motivation is the analysis of critical prewetting, which
corresponds to the choice of a linear external potential.
  We also present partial results on critical prewetting in the two dimensional
Ising model, as well as a few (weak) results on pathwise estimates for the pure
wetting problem for effective interface models.
