We propose a mechanism of electronic control of the polarization of the light emitted by polariton lasers. An electric field applied along the growth axis of the microcavity splits the ground polariton state into [110] and [1-1̄0] polarized components. We perform kinetic simulations which show that above a pumping threshold, a condensate of exciton polaritons is formed at the lowest-energy state. In this regime, the emission of the polariton laser is either [110] or [1-1̄0] linearly polarized depending on the direction of the applied field.