With dissolution little over a month away, we’re not going to see any more by-elections this parliament. Even if an MP dies in the next few weeks, convention dictates their seat will remain vacant until the general election on 7 May.
It means that the total number of by-elections in the 2010-15 parliament stands at 21. This is the highest amount since the 1987-92 parliament:
The different lengths of the parliaments of the past half-century make it tricky to discern any pattern in the number of by-elections, though it’s clear the overall volume has declined. Consider the four-year Labour government of 1966-70, when 38 by-elections took place: that’s over six times the number that took place in the four-year Labour government of 2001-05.
This graph gives a better picture of how the frequency of contests has changed:
You can see there is a general trend downwards, perhaps summed up by the years when there have been no by-elections at all – 1992, 1998 and 2010 – falling within the second half of the 50-year span. The sudden spike in 1986 is to do with the decision by 15 Northern Ireland MPs to resign in opposition to the Anglo-Irish Agreement and seek re-election (which all but one achieved).
Even though we’ve had a relatively high number of by-elections in this parliament, the number of seats changing hands has been quite low:
This last graph suggests another trend: one of by-elections becoming less an opportunity for defeating the incumbent and more an exercise in parties holding their seats. Only one marginal changed hands: Corby, won by Labour from the Tories.
Two by-elections from this parliament made it into the top 10 of largest swings seen in any by-election from the past 100 years. They were Douglas Carswell’s victory for Ukip in Clacton and George Galloway’s win for Respect in Bradford West:
Note that most of these swings were achieved by smaller parties: three by the Liberals/Lib Dems; two by the SNP; and one each by Ukip and Respect. Of the two big parties, Labour only makes three appearances in the top 10, while the Tories do not appear at all.
Of all the parliaments of the past 50 years, 1966-70 was clearly the bumper period for by-election fans. Not only were there a whopping 38 contests in total, 16 of them saw a seat change hands. I suspect the days of such a high turnover of MPs are long gone. This will disappoint those who are partial to the late-night thrill of a by-election – but greatly relieve those whose job it will be to piece together the next government in what will most likely be another hung parliament.