  We examine the possibility of detecting effects of leptonic CP violation by
precise measurement of the solar neutrinos within the framework of standard
electroweak theory minimally extended to include neutrino masses and mixing. We
prove a ``no-go theorem'' which states that effects of CP violating phase
disappear in the nu_e survival probability to the leading order in electroweak
interaction. The effects due to the next-to-leading order correction is
estimated to be extremely small, effectively closing the door to the
possibility we intended to pursue.
