The BBC say:
One poll of 130 Liberal Democrat constituency association chairmen found that nearly a third were not convinced Sir Menzies was doing well.
However, when you look at the detail it is not exactly a "slam dunk" finding. 9 chairs out of 90 contacted said they did not support Ming. So 90% were either satisfied, unsure or didn't answer. Mind you, five refused to answer. So you could say they didn't support him, so that's 14 out of 90. Not exactly convincing.
Of the 90 who responded to BBC Radio 4's World This Weekend, 61 said they were satisfied he was leading them in the right direction, 15 were unsure and nine did not support him. The remainder refused to answer.