Safe Seats: Are MPs really at risk?

First posted 13 September 2009

An MP stands a risk of losing his or her job at every general election. If their electorate is dissatisfied they can be sacked. But how many MPs are genuinely at risk of losing their seat? This analysis looks at the facts from history and estimates which current MPs are immune from public opinion.

1. The last General Election in 2005

Let's start by looking at the results of the most recent general election in May 2005 and comparing it with the result of the previous election in June 2001. We can see the summary of the result and changes in this table:

Party	Old Votes	New Votes	Old Seats	New Seats	Held	Gains	Losses
CON	32.7%	33.2%	165	198	162	36	3
LAB	42.0%	36.2%	403	356	356	0	47
LIB	18.8%	22.6%	51	62	46	16	5
NAT	2.6%	2.2%	8	9	7	2	1
OTH	3.8%	5.7%	1	3	1	2	0
Total	100%	100%	628	628	572	56	56

There was a swing of 3.2% to the Conservatives from Labour, and 56 seats changed hands. Of the 628 seats in Great Britain, that means only 9% of seats changed hands and 572 (or 91% of seats) did not change.

In other words, more than 9 out 10 MPs were not replaced by the electorate. Though some MPs would have given up their seats due to retirement, death, or deselection by their party.

2. Recent General Elections since 1987

But 2005 was quite a "stable" result with the Labour government re-elected and not much change in the overall political environment. We can look at results over the last 20 years or so to see a broader picture.

Election	Comment	Swing to Con	Total Seats	Seats Held	Seats Changed	Changed %
1987	Con re-elected	-1.8%	633	589	44	7%
1992	Con re-elected	-2.1%	633	580	53	8%
1997	Lab elected	-10.3%	641	461	180	28%
2001	Lab re-elected	1.8%	641	620	21	3%
2005	Lab re-elected	3.2%	628	572	56	9%

Apart from Labour's landslide victory in 1997, fewer than one in ten seats changed hands at any election. Even in 1997 when there was a large swing of 10% in favour of Labour, fewer than three in ten seats changed hands. In other words, more than seven out of every ten MPs were not changed by voters.

3. All General Elections since 1906

We can also take a long view of all the general elections in modern times. There have been 27 elections since 1906, including several landslides and major changes in political support. The graph shows, for each of these elections:

The swing to (or from) the Conservatives from (or to) the other two major parties [red bar chart]
The fraction of seats in the House of Commons which changed hands [blue line]

The graph tells us about both extremes and typical elections:

The election with the greatest change was the 1931 victory by Stanley Baldwin's Conservatives (and National Government). There was a swing of 23%, and about 42% of seats changed hands. Even in this electoral whirlwind, most MPs kept their seats.
Other than this extreme case, swings were always below 15%, and (usually) fewer than 30% of seats changed hands.

4. Predictions for the next General Election

The current predicted swing (as at 9 September 2009) is a swing of 9% towards the Conservatives away from Labour. This is a large swing and could give the Conservatives a sizable majority. Even so, this is within the historical range of swings of up to 15% that we have seen over the last century. The number of seats which are predicted to change is 172, which is 27% of the 632 seats in Great Britain. This is also within the usual limit of 30% which we saw in the historical data.

So, even if the Conservatives win with a large swing, seven out of ten MPs will be safe.

But the political situation could change by the next election. Labour could recover or the Liberal Democrats could have a resurgence in support. In this case, the seats which appear "safe" or "unsafe" could be very different. To allow for this, we have run a number of scenarios to explore various possibilities. Each scenario represents an extreme movement in public support from May 2005 to the next general election. Full details of the scenarios are described here.

Even under all these extreme scenarios, 319 seats never change their party and only 313 seats can change. This means that over half of all MPs are in safe seats no matter what happens to public opinion.

You can see whether any seat is safe or not, by looking in the alphabetical list of seat predictions (England A-B, etc). A seat will have one of the legends:

5. How to "kick the rascals out"

It is sometimes said that the true test of a democracy is not just whether it is possible to elect your favoured candidate, but whether it is possible to get rid of an incumbent that you dislike. For countries around the world, that provides an interesting acid test which separates the true democracy from the sham elections of a one-party state.

But closer to home, it also gives us pause for thought. British democracy clearly lets the people kick out governments which they dislike, such as in 1997, 1979, 1974 and many times before. This is a great strength of the first-past-the-post electoral system, which is lacking in many systems of proportional representation. However, it is difficult to get rid of an individual unpopular MP. If the MP is in a marginal seat, then he or she can be removed. But if the seat is safe, then it is hard for voters to remove an MP. If the MP's party is popular with voters, but the particular MP is not, then voters are deprived of a means to express their preference. Only the party can do that through deselection, which is both uncommon and undemocratic.

One answer to this problem is to encourage parties to hold primary elections to select their candidate for the next general election. A primary election is a pre-election to choose a party's candidate. The candidates in the primary are members of that party who want to be the official party candidate in the general election. The voters in the primary election can be all the voters in that seat (an open primary), though mostly only the supporters of that party will take the trouble to vote in the party's primary.

Primary Elections have long been popular in the United States, and have now begun to be used in the United Kingdom. The first one was a Conservative party primary in Totnes held in August 2009.

Primary Elections give voters in safe seats a real say over who their MP is. That could bring real democratic choice of MP to the 50% of people who currently live in safe seats.

Appendix: Technical Notes

The data was prepared using the following assumptions and methodology:

Election comparisons (1987 onwards) have been made comparing like with like. Where new boundaries have come into effect, seats are compared with the notional result of the previous election as if run under the new boundaries. Northern Ireland is excluded.
Data for elections up to 1983 have been drawn from British Political Facts 1900-1994 by David Butler and Gareth Butler. These results do not contain explicit totals for seats changing hands, so these have been estimated from seat totals won by each party.
For the long historical series swings have been calculated between the Conservative party and the sum of the Labour and Liberal parties.