  We develop an alternative formulation of the symmetry breaking sector of the
Standard Model as a gauged non-linear sigma model (NLSM) following the
philosophy of the Chiral lagrangian approach, which is the only compatible with
all the experimental and theoretical constraints. We derive the BRS symmetry of
the model and the corresponding quantum lagrangian, which is a generalization
of the standard Faddeev-Popov method, in a way which is covariant with respect
to the reparametrizations of the coset space of the NLSM. Then we use the BRS
invariance of the quantum lagrangian to state the Equivalence Theorem for the
renormalized $S$-matrix elements calculated as a chiral expansion.
