  Electroweak corrections to longitudinal gauge and Higgs boson scattering
amplitudes are calculated. Due to Sudakov double logarithms, the effect is a
suppression of amplitude that grows rapidly with increasing center of mass
energy leading to significant reduction of cross sections compared to tree
level results. For example, the suppression factor for the cross section of
$W^+_{\text{L}}W^-_{\text{L}}$ scattering due to these corrections varies from
0.3 at the center of mass energy of $100\text{TeV}$ to a factor of $10^{-12}$
at the center of mass energy of $10^{13}\text{TeV}$. The modification of SM
unitarity bound due to these corrections is obtained.
