  We demonstrate that the neutrino kinetic equation derived by the standard
Bogolyubov method is formally gauge non-invariant and give a recipe how to
recast it to the gauge invariant form recovering the standard Lorentz form weak
force term which apparently conserves the lepton current. The analogy with the
QED plasma case is traced which in asymptotic regions implies substitution of
electric charge $e$ by the induced electric charge $e_{\nu}^{ind}$ of neutrino
within the phase factor connecting neutrino gauge invariant and non-invariant
distribution functions.
