  The aim of this paper is to analyze a viscoelastic phase separation model. We
derive a suitable notion of the relative energy taking into account the
non-convex nature of the energy law for the viscoelastic phase separation. This
allows us to prove the weak-strong uniqueness principle. We will provide the
estimates for the full model in two space dimensions. For a reduced model we
present the estimates in three space dimensions and derive conditional relative
energy estimates.
