I'm not saying it's impossible but it's highly improbable, even if the second placed Labour vote completely collapsed.
However, this becomes interesting if Parish himself stands as he's threatened to do
I do agree that although Labour came second they stand absolutely no chance of winning and the Tory vote collapsing will most likely benefit the LibDems but that Tory Majority is HUGE
Even prior to 2015 when the LibDem vote collapsed (for their Tory Collaboration) and they were the real opposition to the Tories in the South West, they still didn't win this one. They came within 2k the first time the seat was contested in 1997 but since then, not even close.
By-elections can be strange beasts as we all know but the Tories have never got less than 41% of the vote (1997) and increased their share every election until the last one, where it dropped by 1% but was still over 60%
If the LibDems do win it, the Tory Party will collectively shit itself