  We study the dynamics of a tracer particle subject to a constant driving
force $E$ in a one-dimensional lattice gas of hard-core particles whose
transition rates are symmetric. We show that the mean displacement of the
driven tracer grows in time, $t$, as $ \sqrt{\alpha t}$, rather than the linear
time dependence found for driven diffusion in the bath of non-interacting
(ghost) particles. The prefactor $\alpha$ is determined implicitly, as the
solution of a transcendental equation, for an arbitrary magnitude of the
driving force and an arbitrary concentration of the lattice gas particles. In
limiting cases the prefactor is obtained explicitly. Analytical predictions are
seen to be in a good agreement with the results of numerical simulations.
