Ward identities and gauge flow for M-theory in {cal N}{=}3 superspace

We derive the BRST symmetry, Slavnov-Taylor identities and Nielsen identities for the ABJM theories in ${\cal N}{=}3$ harmonic superspace. Further, the gauge dependence of one-particle irreducible amplitudes in such superconformal Chern-Simons theory is shown to be generated by a canonical flow with respect to the extended Slavnov-Taylor identity, induced by the extended BRST transformations (including the BRST transformations of the gauge parameters).