We discuss lepton charge asymmetries in tt and ttγ production at the LHC, which can be measured in the semileptonic decay channel tt → W + b W −b → + νb qq b (or the charge conjugate). Considering several variants of a new physics scenario with a light colour octet, it is seen that for tt these asymmetries may have a sensitivity competitive with the dilepton asymmetry already measured. For ttγ the new leptonic asymmetries, as well as the tt charge asymmetry, will reach their full potential with the high luminosity LHC upgrade. These asymmetries can pinpoint deviations at the 3σ −4σ level for new physics scenarios where the charge asymmetries already measured in tt production agree within 1σ .