  We study the large deviations of the distribution P(W_\tau) of the work
associated with the propulsion of individual active brownian particles in a
time interval \tau, in the region of the phase diagram where macroscopic phase
separation takes place. P(W_\tau) is characterised by two peaks, associated to
particles in the gaseous and in the clusterised phases, and two separate
non-convex branches. Accordingly, the generating function of W_\tau cumulants
displays a double singularity. We discuss the origin of such non-convex
branches in terms of the peculiar dynamics of the system phases, and the
relation between the observation time \tau and the typical persistence times of
the particles in the two phases.
