it's a fair point, Lib Dems are one of the few anti-Brexit parties out their and are likely to pick up a few votes becuase of that, but their spell in coalition government and the basic selling of the parties vote for that Alternative Vote Referendum, really hurt the party, can't see them making much gains, their hardly poling better then they did in 2015.
UKIP seem completely irrelevant now, the main thing they have been arguing for is happening.....they seem to have no idea what to do now, i expect them to drift away into irrelevance.