The pieces of the electoral pie that have got to get a lot smaller if Cameron is to have any chance of staying at Number 10
2010 LD to LAB switching
2010 CON to UKIP switching
Thanks to the new Populus monthly polling aggregate with a sample in February of 14,203 and the weekly averaging of the numbers in the five times a week YouGov polling we can get broader picture of the big dynamics in voting intentions since the 2010 general election.
The pie charts above say it all. At the last general election the Lib Dem secured 24% of the overall GB vote while the Tories chalked up 37%. So switching on any scale by LD voters to LAB and CON ones to UKIP is going to seriously undermine the Conservative re-election effort.
I plan to monitor this very carefully in the 14 months that remain.
My guess is that both will get smaller -the question is whether the change will be enough.