Rising Bosonic Electroweak Virtual Effects at High Energy e+e- Colliders

The virtual massive gauge boson effects on several observables in the process of charged fermion pair production at ${e}^{+}{e}^{\ensuremath{-}}$ colliders are computed up to the TeV energy range in the standard model, working in the ``$Z$-peak-subtracted'' representation. It is shown that these effects increase regularly with energy, approaching the typical 10% relative size. A careful numerical evaluation is proposed, where the conditions dictated by gauge invariance are consistently implemented.