  Predictions of the number of faint polarised radio sources that can be
detected by SKA pathfinder telescopes and the SKA depend on the polarisation
properties of radio sources with a total flux density around 1 mJy. Total
intensity source counts suggest a transition in the dominant population from
AGN to galaxies around this flux density, and the properties of brighter radio
sources may not be representative for this fainter population. We show that
unresolved spiral galaxies can be highly polarised radio sources, up to ~ 20%
polarised at 4.8 GHz. This result is partly based on observations of nearby
galaxies, including galaxies with significant deviations from axial symmetry
and other peculiarities. A first analysis of polarised source counts divided
into steep-spectrum AGN, flat-spectrum AGN and star forming galaxies is
presented, including a prediction of polarised source counts to microjansky
levels.
