Leptonic CP problem in left-right symmetric model

We find using the minimal left-right symmetric model that the presence of leptonic CP violation can radiatively generate a strong CP phase at the one-loop level itself, which can be beyond the current bounds established by the neutron electic dipole moment experiments. If there are no axions or unnatural cancellations, this leads to the testable prediction that leptonic CP violation must be negligibly small (Dirac phase ${\delta }_{CP}=0$ or $\pi$), in a wide and interesting region of parameter space.