  An action for 3+1-dimensional supergravity genuinely invariant under the
Poincare supergroup is proposed. The construction of the action is carried out
considering a bosonic lagrangian invariant under both local Lorentz rotations
and local Poincare translations as well as under diffeomorphism, and therefore
the Poincare algebra closes off-shell. Since the lagrangian is invariant under
the Poincare supergroup, the supersymmetry algebra closes off shell without the
need of auxiliary fields.
