Flute perturbations of a strongly inhomogeneous dilute plasma in an inhomogeneous electric field are discussed. An inhomogeneous electric field, appearing at weak charge separation in a region with a width of the order of an ion Larmor radius in which plasma, is inhomogeneous, does not affect the stability of long-wave oscillations of low frequency. Also examined is the case of a very strong inhomogeneity in which the characteristic dimension at which the electric field changes is the order of an electron Debye length. In this case perturbations with a wavelength the order of an inhomogeneity dimension can be unstable.