  We consider theoretically transport in a spinfull one-channel interacting
quantum wire placed in an external magnetic field. For the case of two
point-like impurities embedded in the wire, under a small voltage bias the
spin-polarized current occurs at special points in the parameter space, tunable
by a single parameter. At sufficiently low temperatures complete
spin-polarization may be achieved, provided repulsive interaction between
electrons is not too strong.
