In post-war history, the UK has tended to have single-party governments which enjoy a majority in the House of Commons. When a minority government needed support from a smaller party it has always been the Liberal Democrats (Con/Lib Coalition government 2010-2015), and its Liberal Party predecessor (Lib-Lab pact, 1977-1978). However, the recent Scottish Independence referendum in September 2014 has transformed the landscape for coalition building. This article describes how the changes in Scotland affect the rest of the UK, and explores the new possibilities in the event of a hung parliament.
Scotland in recent years has returned a large bloc of Labour MPs. In 2010, Scottish Labour received 42% of the votes in Scotland and won 41 out of 59 seats. This group has traditionally formed a significant part of the parliamentary Labour party. The SNP, by contrast, received 20% of the votes and won only 6 seats. However, despite losing the referendum vote, the SNP has been energised by the independence campaign and its party membership has soared. It has also increased its predicted Westminster voting intention level to 43% (as at November 2014), whilst Labour has fallen to 27%. This would reverse the previous Scottish election result, and could see the Nationalists win about 47 seats, with Labour reduced to 11 seats. This change would have two major effects. Firstly, the loss of thirty seats makes it harder for Labour to have an overall majority at Westminster. And secondly it makes it likely that the SNP would be the third largest party in the House of Commons, which completely transforms the possibilities for coalitions and pacts.
Electoral Calculus has run a large number of scenarios to explore this new world of hung parliament possibilities, and to estimate their probabilities. The overall complexity is best shown with the following graphic:
Source: Electoral Calculus
Currently there is about a 50% chance of a hung parliament in 2015, and this graphic shows the battleground area focusing on the hung parliament scenarios. The growth of SNP support in Scotland creates a genuine four-party system at Westminster with a range of possible coalition permutations. Conservative support is given by the horizontal axis, and Labour support by the vertical axis. The current support position (Con 30.7%, Lab 33.2% at December 2014) is shown by the circular blue marker inside the "Lab choice of Lib/Nat" zone, where Labour can choose its coalition partner.
The map only shows movement for the Conservative, Labour and Liberal Democrat parties. It assumes the votes for other parties, including UKIP and the SNP, are fixed at current support levels. UKIP are not currently to predicted to win many seats, so they are not yet a factor in coalition permutations. Since other parties have 28% support nationally, the map is missing the top-right corner where the Conservative plus Labour total would be more than 72%.
Previously there were only a limited number of two-party coalition possibilities because the only likely partner was the Liberal Democrats. So the two-party options were limited to a Con/Lib coalition and a Lab/Lib coalition, with an interesting sub-case being when both options were possible at the same time, and the Liberal Democrats might effectively be able to choose between the two major parties to select which forms the government. Technically that gives six possibilities (Labour majority, Lab/Lib coalition, Lib choice of Con/Lab, no overall control, Con/Lib coalition, and Conservative majority).
But the arrival of a large bloc of SNP MPs would increase the number of possible two-party permutations to twelve. Here is the description of these possibilities for coalition government, going clockwise from top-left:
The table below shows possible examples of each of the twelve scenarios. Note that the examples of the first seven types can be found without even changing the current Liberal Democrat support level and only by varying Labour support within the narrow range between 28.6% and 35.0%.
|1. Labour majority|
Labour majority of 22
|2. Lab choice of Lib/Nat|
Labour need six seats - could be LibDem, SNP, or DUP
|3. Lab/Nat coalition|
Labour need 29 seats - only SNP have enough
|4. Nat choice of Con/Lab|
Labour need 40 seats, Conservatives need 46 seats. SNP have enough for either
|5. Con/Nat coalition|
Conservatives need 24 - only SNP have enough
|6. Conservative majority|
Conservative majority of 30
|7. Con choice of Lib/Nat|
Conservatives need 8 seats - could be LibDem or SNP
|8. Con/Lib coalition|
Conservatives need 64 seats - only LibDems have enough
|9. Lib choice of Con/Lab|
Labour need 85 seats, Conservatives need 90 seats. LibDems have enough for either
|10. LibDem majority|
Lib Dem majority of 28
|11. Lab/Lib coalition|
Labour need 71 seats - only LibDems have enough
|12. No overall control|
Labour need 59 seats. Conservatives need 66 seats. No other single party has enough.
The current probabilities of these scenarios can be seen on the home page. As at December 2014, they were:
|Labour majority (1)|
|Lab/Nat coalition (3)|
|Lab choice of Lib/Nat (2)|
|Con/Nat coalition (5)|
|Conservative majority (6)|
|Nat choice of Con/Lab (4)|
|Con choice of Lib/Nat (7)|
|No overall control (12)|
So the probability of a good outcome for Labour (options 1, 2, 3, 4, 11) where Ed Miliband is Prime Minister is 77%. The probability of a good outcome for the Conservatives (options 6, 7, 8) with David Cameron staying in Downing Street is only 12%. A good outcome for the SNP (options 3, 4, 5) has them controlling the balance of power, with a probability of 33%. A good outcome for the Liberal Democrats (options 2, 7, 8, 9, 10, 11) has probability of 16%.
These probabilities will change as the election approaches.
Even the list of twelve scenarios above is not exhaustive and other outcomes can happen. In brief, they are: