Limiting fluctuations in quantum gravity to diffeomorphisms

Within the background field formalism of quantum gravity, I show that if fluctuations are limited to diffeomorphic gauge transformations rather than physical degrees freedom, as in conventional theory, all corrections vanish on shell and effective action is equivalent classical action. In principle, resulting theory finite unitary, requires no renormalization. also this unique parameterization renders path integral independent on-shell condition for field, a form independence. Thus, connection established between independence renormalizability unitarity.