  New fibre spectroscopy and radial velocities from the WIYN telescope are used
to measure photospheric lithium in 242 high-probability, zero-age-main-sequence
(ZAMS) F- to K-type members of the rich cluster M35. Combining these with
published rotation periods, the connection between lithium depletion and
rotation is studied in unprecedented detail. At $T_{\rm eff}<5500$ K there is a
strong relationship between faster rotation and less Li depletion, although
with a dispersion larger than measurement uncertainties. Components of
photometrically identified binary systems follow the same relationship. A
correlation is also established between faster rotation rate (or smaller Rossby
number), decreased Li depletion and larger stellar radius at a given $T_{\rm
eff}$. These results support models where starspots and interior magnetic
fields lead to inflated radii and reduced Li depletion during the pre main
sequence (PMS) phase for the fastest rotators. However, the data are also
consistent with the idea that all stars suffered lower levels of Li depletion
than predicted by standard PMS models, perhaps because of deficiencies in those
models or because saturated levels of magnetic activity suppress Li depletion
equally in PMS stars of similar $T_{\rm eff}$ regardless of rotation rate, and
that slower rotators subsequently experience more mixing and post-PMS Li
depletion.
