  We develop a minimal left-right symmetric model based on the gauge group
$SU(3)_C \otimes SU(2)_L \otimes SU(2)_R \otimes U(1)_{B-L}$ wherein the Higgs
triplets conventionally employed for symmetry breaking are replaced by Higgs
doublets. Majorana masses for the right-handed neutrinos $(\nu_R$) are induced
via two-loop diagrams involving a charged scalar field $\eta^+$. This setup is
shown to provide excellent fits to neutrino oscillation data via the seesaw
mechanism for the entire range of the $W_R^\pm$ mass, from TeV to the GUT
scale. When the $W_R^\pm$ mass is at the TeV scale, the $\nu_R$ masses turn out
to be in the MeV range. We analyze constraints from low energy experiments,
early universe cosmology and from supernova 1987a on such a scenario and show
its consistency. We also study collider implications of a relatively light
$\eta^+$ scalar through its decay into multi-lepton final states and derive a
lower limit of 390 GeV on its mass from the LHC, which can be improved to 555
GeV in its high luminosity run.
