More importantly, will Farage stand in this by-election ? Farage and UKIP are very unpredictable in everything that they do but it may not be the best seat for Farage to make his entry into Westminster. See this link for all the recent election results for Newark :::
http://en.wikipedia.org/wiki/Newark_(UK_Parliament_constituency)
As can be seen, UKIP have failed badly in the last two elections in this constituency. According to The Today program this morning, recent boundary changes have made this an even more safe Tory seat than it was today, so it would appear that Labour have a reduced chance of winning. For UKIP to win in Newark it would need to go from the 3.8% that it achieved in 2010, to near or over 50%...not completely unprecedented but a very rare event indeed.
Farage has an important decision to make today. If he stands, and loses, it would put his chances of UKIP's success in 2015 back considerably. But if he stands and wins, it would give UKIP the boost in credibility that the party so badly needs.
If Boris decides to stand as well, then all bets are off !