  The elastic and inelastic high--energy small--angle electron--positron
scattering is considered. All radiative corrections to the cross--section with
the relative accuracy $\delta\sigma/ \sigma = 0.1 \% $ are explicitly taken
into account. According to the generalized eikonal representation for the
elastic amplitude, in higher orders only diagrams with one exchanged photon may
be considered. Single photon emission with radiative corrections and
next--to--leading two--photon and pair production diagrams are evaluated,
together with leading three--loop corrections. All contributions have been
calculated analytically. We integrate the calculated distributions over typical
for LEP~1 experiments intervals of angles and energies. To the leading
approximation, the results are shown to be described in terms of kernels of
electron structure functions. Some numerical results are presented.
  PACS numbers 12.15.Lk, 12.20.--m, 12.20.Ds, 13.40.--f
