  We investigate dynamical chiral symmetry breaking in unquenched ${QED}_3$
using the coupled set of Dyson--Schwinger equations for the fermion and photon
propagators. For the fermion-photon interaction we employ an ansatz which
satisfies its Ward--Green--Takahashi identity. We present self-consistent
analytical solutions in the infrared as well as numerical results for all
momenta. In Landau gauge, we find a phase transition at a critical number of
flavours of $N_f^{\mathrm crit} \approx 4$. In the chirally symmetric phase the
infrared behaviour of the propagators is described by power laws with
interrelated exponents. For $N_f=1$ and $N_f=2$ we find small values for the
chiral condensate in accordance with bounds from recent lattice calculations.
We investigate the Dyson--Schwinger equations in other linear covariant gauges
as well. A comparison of their solutions to the accordingly transformed Landau
gauge solutions shows that the quenched solutions are approximately gauge
covariant, but reveals a significant amount of violation of gauge covariance
for the unquenched solutions.
