  We generalize the recoil polarization method for the determination of the
proton form factor to the case of the disintegration of vector polarized
deuterons by longitudinally polarized electrons, $\vec d(\vec e, e'n)p$. We
suggest to measure for this reaction, in the kinematics of quasi-elastic
$en$-scattering, the ratio $R_{xz}=A_x/A_z$ of the asymmetries induced by the
$x$- and $z$-components of the deuteron vector polarization. In the framework
of the relativistic impulse approximation the ratio $R_{xz}$ is sensitive to
$G_{En}$ in a wide interval of momentum transfer squared, whereas it depends
weakly on the details of the $np$-interaction and on the choice of the deuteron
wave function. Moreover, in the range $0.5\le Q^2\le$1.5 GeV$^2$, the ratio
$R_{xz}$ shows a smooth dependence on $Q^2$, making the analysis simpler.
