1999MNRAS.309..189J

I present the results of a programme to monitor the strengths of the Lii 6708Å, Ki 7699Å and chromospheric Hα lines in a group of cool Pleiades stars. Consistent instrumentation and analysis techniques are used to show that there is no Lii variability on time-scales of 1 year that could possibly account for the apparent spread in Li abundances seen in Pleiades stars between effective temperatures of 4800 and 5200K. Comparison with published data reveals tentative evidence for variability on 10-year time-scales, but at a very low level. The lack of chromospheric activity variability above levels of 20 to 30per cent makes it difficult, however, to rule out evenly distributed magnetic activity regions causing a scatter in the Lii line strengths at a given abundance. The similar star to star scatter of Ki line strengths in these and published data reinforces the conclusion that it is still unsafe to attribute the Lii line strength dispersion to a large variation in Li depletion at a given mass.