  We study interacting run and tumble particles in two dimensions, both on a
lattice and in continuum, where particles move in the direction of their
internal orientation. These motile particles can tumble and change their
internal orientation with a fixed rate $\omega;$ $\omega^{-1}$ quantifies the
motility. Starting from interacting particle systems that exhibit phase
separation transitions in the absence of motility, we ask how the ordering in
the system changes when motility is added and increased. We observe that
increased motility impedes cluster formation in a large class of models
including conserved lattice gas, driven lattice gas, and interacting hard-disc
models in continuum, and explain why. We further show that a stable
phase-separated state is ruled out in the absence of any attractive
interaction.
