Leptonic low energy CP phases, of Dirac as well as Majorana type, can be predicted
with the help of flavour and CP symmetries. However, the high energy CP phases in
the lepton sector, relevant for leptogenesis, are in general unrelated to those at low
energies and thus represent new sources of CP violation. We discuss a scenario in which
all CP phases are constrained by flavour and CP symmetries. In this way, the CP
violation at low and high energies becomes intimately related and, in particular, the
sign of the baryon asymmetry of the Universe, generated via the mechanism of unflavoured
leptogenesis, is fixed.