  We investigate the possibility of using future photometric and radio surveys
to constrain the power spectrum of primordial fluctuations that is predicted by
inflationary models with a violation of the slow-roll phase. We forecast
constraints with a Fisher analysis on the amplitude of the parametrized
features on ultra-large scales, in order to assess whether these could be
distinguishable over the cosmic variance. We find that the next generation of
photometric and radio surveys has the potential to test these models at a
sensitivity better than current CMB experiments and that the synergy between
galaxy and CMB observations is able to constrain models with many extra
parameters. In particular, an SKA continuum survey with a huge sky coverage and
a flux threshold of a few $\mu$Jy could confirm the presence of a new phase in
the early Universe at more than 3$\sigma$.
