  The potential of the LHeC, a future electron-proton collider, for precision
Deep Inelastic Scattering measurements is reviewed with particular emphasis on
the reduction of uncertainties on the parton distribution functions (PDFs) of
the proton and on the measurement of $\alpha_s(M_Z)$. The interpretation of
possible Beyond Standard Model (BSM) signals at the LHC is crucially dependent
on precise knowledge of the predictions of the Standard Model (SM) and the
uncertainties on PDFs and $\alpha_s(M_Z) $are a limiting factor. The LHeC
project, running in parallel with later stages of LHC running, would provide
much improved precision on the PDFs as compared to the precision expected from
LHC data alone.
