  The canonical structure of the massive gravity in the first order moving
frame formalism is studied. We work in the simplified context of translation
invariant fields, with mass terms given by general non-derivative interactions,
invariant under the diagonal Lorentz group, depending on the moving frame as
well as a fixed reference frame. We prove that the only mass terms which give 5
propagating degrees of freedom are the dRGT mass terms, namely those which are
linear in the lapse. We also complete the Hamiltonian analysis with the
dynamical evolution of the system.
