So just what is a by-election for? At its most basic it is replace the predecessor through a short election process. But increasingly, and this apples to all parties, it is an exercise in organisational strength and is heavily swayed by the immediate past electoral history.

Who are the candidates is at risk of being a side show, a lesser question, than the need to get a replacement in post from the previous party. This comes through in many different ways, but risks suffocating the choice itself for the local electorate.

I have been to many by-elections over many years (though not as many as Lord Roger Roberts - he says his first was to support Frank Owen in Hereford...!) and over time you see a lot of candidates of varying quality. I can say with all sincerity and confidence that Liz Leffman is outstanding and would be a great representative in Parliament for the people of Witney constituency and West Oxfordshire.

Liz is one of those people who is calm, reassuring, thorough, assiduous and gives an air of being incapable of panic. She is sensible and reasonable whilst having a strong and articulate radical streak. Prepared to stand alone, willing to be counted, able to lead people and represent communities.  It's  really very inspiring.

Hustings (where the public question the candidates) are fewer and fewer, it seems, but they provide a great chance to test the candidates and enable their talents to be seen and their weaknesses to be tested. As long as they are not set-ups and bear baiting opportunities they can reveal just what is at stake and see the true qualities shine through. Four or five weeks, no matter how energetic and how experienced the team, is often not enough to change decades of voting tradition. But sometimes, just sometimes, earthquakes happen.

Here in Witney it has been a great Lib Dem campaign, due in part to having a great candidate in Liz. The literature has been delivered, the messages have got through, Liz is seen and known locally across the patch - the challenge is getting the votes out on Polling Day this Thursday.

I look forward to seeing lots of old friends over the next 48 hours and making some new one as you all pour in to help Liz Leffman. She very very impressive and well worth making the effort for. I hope you can come over.