The monthly Electoral Calculus general election projection is out and as can be seen from the chart LAB is given a 79% chance of an overall majority.
In seat terms Electoral Calculus is projecting a LAB majority of 80 which is seven up on a month ago. The seat breakdown is CON 231 (-76): LAB 365 (+107): LD 23 (-34): SNP/PC 12 (+3): UKIP 0 (=)
The key part of the Electoral Calculus approach is the assumption of a universal national swing. This can be upset by two main factors:
Incumbents, particularly first time ones, doing better.
Differential swings in the marginal seats which was highlighted earlier in the month by the 12,000 sample phone poll carried out by Lord Ashcroft. This pointed to a disproportionately higher CON>LAB swing in the key battlegrounds
The latest trade on the Betfair GE2015 outcome market point to the chances of a CON majority of 24.4% which is substantially higher than the Electoral Calculus figures.
Chances of LAB majority edge up on Betfair's GE2015 market See table based on latest trades pic.twitter.com/oxHEfAkCH7
— Mike Smithson (@MSmithsonPB) September 30, 2013