at NNLL order, a systematic treatment of electroweak effects at the same level has not yet been accomplished. Electroweak corrections are responsible for a variety of different physical effects. At leading order, the three basic electroweak effects are the $e^+e^-$ annihilation process that leads to top pair production by virtual photon and Z exchange, the finite top lifetime, which can be implemented by the replacement rule $E\to E+i\Gamma_t$ [@Fadin1] ($E=\sqrt{s}-2m_t$ being the c.m.energy with respect to the top threshold and $\Gamma_t$ being the on-shell top quark width), and the luminosity spectrum mentioned above. All three effects have so far been treated independently. It has become the convention that only the first two effects are included into theoretical predictions while the luminosity spectrum is accounted for in the experimental simulations [@TTbarsim].

At the subleading level a coherent treatment of electroweak effects has not yet been achieved, although previous partial analyses have indicated that they can reach the level of a few percent [@GuthKuehn; @HoangTeubnerdist]. It is also evident that at the subleading level an independent treatment of various different electroweak effects will, eventually, be impossible. Since a systematic treatment relies on the consistent separation of off-shell (non-resonant) and close-to-mass-shell (resonant) fluctuations, 