feature have very faint B-band magnitudes, with a substantial fraction (62%) below the $3\sigma$ detection limit in this band ($B_{lim} = 28.4$). A non-detection in the $B$-band does not affect their classification, however, and merely pushes them red-ward in B-z colour in the BzK diagram illustrated in Figure 1. The more worrying class are the objects which are below the $3\sigma$ limit in $z'$ [*and*]{} $B$, which cannot be assigned BzK classification (164 objects). Figure \[kzk\] shows that even within our K-band limit, we become incomplete above $(z - K) \simeq 3$. We study the effect of this incompleteness by considering the extreme case in which all of the objects with B- and $z^{\prime}$-band magnitudes fainter than the $3\sigma$ limits (28.4 and 26.7 respectively) are pBzKs. In this ’worst case’ sample the number counts still exhibit a plateau, as before, but with the absence of a turn-over.

At our conservative limit of $K_{AB}< 23$ our completeness is $> 95$% for compact galaxies (Almaini et al., in prep.), so the feature is unlikely to be due to $K$-band incompleteness unless there is unprecedented size-evolution in the pBzK population towards fainter magnitudes compared to the general population. The extreme compactness of passive 