Аннотация:We consider classical gauge theory with spontaneous symmetry breaking on a principal bundle P->X whose structure group G is reducible to a closed subgroup H, and sections of the quotient bundle P/H->X are treated as classical Higgs fields. In this theory, matter fields with an exact symmetry group H are described by sections of a composite bundle Y->P/H->X. We show that their gauge G-invariant Lagrangian necessarily factorizes through a vertical covariant differential on Y defined by a principal connection on an H-principal bundle P-> P/H (Theorems 5 and 6).