Electroweak and non-resonant corrections to top-pair production near threshold at NNLO

The top-quark mass can be determined with very high precision from a scan of the total $e^{+}{e}^{-}\to b\bar{b}{W}^{+}{W}^{-}X$ cross section near the top-pair production threshold. We present the full calculation of electroweak and non-resonant corrections to this process at NNLO. We discuss the size of the new contributions and estimate the theory uncertainty on the top-quark mass in the PS mass scheme.