The recent announcement of a Welsh Assembly by-election date prompts the discussion.
2017 has been a reasonably good year for the Liberal Democrats, but could it be about to get better?
From the Liberal Democrats' Sarah Olney to Labour's Michael Carr.
In June’s snap election, the Liberal Democrat made a net gain of four seats, but they can do much better in 2022.
In the event of an early election, these are the seats Theresa May will need to retain to stay in power.
By-elections take place when an MP steps down or dies. Here are seven that have shifted British politics.