Of course, a Lib Dem majoirty govt is the preference.
But given that is highly unlikely, it is an odd position to deny yourself the option of supporting a govt which provides the only path to do that.
Except one is quite literally offering a referendum to stop Brexit. And the other...well, isn't.
Given from their rhetoric I assume they believe Brexit is even more important than austerity, this seems a peculiar volte face.