On the QED radiator at order α3

The O(α3) leading logarithmic contribution to the QED radiator in the additive form is considered. The effect of the correction on two-fermion physics at LEP1 and LEP2 is evaluated and critically compared with the one of next-to-leading O(α2) corrections. A critical comparison with existing estimates for the LEP1 energy range is also performed. The O(α3) leading logarithmic corrections turn out to be relevant in view of the experimental precision already reached at LEP1 and foreseen at LEP2.