  I describe a novel covariant formulation of massive gauge theories in which
the longitudinal polarization vectors do not grow with the energy. Therefore in
the present formalism, differently from the ordinary one, the energy and
coupling power-counting is completely transparent at the level of individual
Feynman diagrams, with obvious advantages both at the conceptual and practical
level.
  Since power-counting is transparent, the high-energy limit of the amplitudes
involving longitudinal particles is immediately taken, and the Equivalence
Theorem is easily demonstrated at all orders in perturbation theory. Since the
formalism makes the Equivalence Theorem self-evident, and because it is based
on a suitable choice of the gauge, we can call it an "Equivalent Gauge".
