Apparently conflicting results of Josephson tunelling experiments in the high- cuprates have been explained by Müller by proposing the coexistence of s-wave and d-wave condensates. We have explained a number of experimental results in the cuprates by assuming that the ionic plasmon promotes the s-wave condensate. As some of the fits are very compelling we propose that the ionic plasmon be accepted as the mediator in the Cooper pairing in this case. We have also explained the existence of a single transition temperature and the existence of the precursor spin-gap phase.