YES: Scotland leaves the Union and takes its Labour cohort with it

A core question here needs to assess how a Yes vote in 9 days will impact upon the political makeup of the Westminster Parliament. This is key as Scotland’s voting patterns in recent general elections have seen strong returns of Labour MPs to London, amounting to 41 of Scotland’s total of 59 MPs in 2010. The maths, therefore, seems rather simple, particularly when we look at the simple proportionality of what the Conservative are set to lose in the event of an independent Scotland; just one.

There is slightly more to this, however. Westminster is underpinned by a first past the post (FPTP) electoral system, meaning that the party which obtains an overall majority – that is at least half, plus one, of all of the 650 seats up for grab – wins. This all important number is currently 326, but of course this is set to change significantly when we factor out the 59 MPs which Scotland normally returns, making the new threshold for victory in a reduced United Kingdom just 296 seats.

What this means is that not only will the Labour party be at least 41 MP worse off, but the Conservatives will be brought much closer to the finishing line with the penalty of losing just one seat. To highlight this point, if we use the electoral calculus to predict the number of seats based on the current national voting intention average of a 3% Labour lead, Ed Miliband is set to win the next general election outright with 13 seat majority, obtaining 339 MPs to the Conservatives’ 268. The calculus indicates that Labour would increase their intake of MPs from Scotland from 41 to 47, meaning that when we both subtract this from the 339 total and lower the threshold of victory to 296, the Labour Party end up being four seats short of winning in the event of a reduced United Kingdom.

with or without scotlandThis of course assumes that Scotland will vote in-line with the national average, and also assumes that the national polls will hold in their current form until the next general election.

If Scotland leaves the Union, not only might unprecedented governance issues mean that the general election will need to be delayed until after 7 May 2015, but the effects that this will have upon voter sentiment in the rest of the UK are at this stage entirely unpredictable.

Therefore, while electoral maths dictates that Scottish independence will make a Labour victory at the 2015 general election less probable, the impact upon voting intention from the political crisis that would likely ensue following a Yes vote would mean that all probabilities would be in need of reassessment.

One final but considerable consequence of Scottish independence is the de facto loss of high-profile MPs currently holding a seat there. These include Gordon Brown, Alistair Darling, Douglas Alexander and Dame Anne Begg from Labour and Charles Kennedy, Danny Alexander and Jo Swinson from the Liberal Democrats.

NO: The Union holds, but the referendum fundamentally changes how Scotland votes

One significant feature of the independence campaign has been the ways in which traditional voters for the Westminster unionist parties are deciding to cast their vote come referendum day. Of the 650 seats across the UK, close to 400 of these are regarded as “safe”. This means that even in the most decisive of elections, only around 250 seats are ever really open to changing hands – the rest represent localities which have always tended to vote one way or another. It just so happens that Scotland is a place which holds a great many Labour “safe seats”, meaning that Westminster voting patterns are typically easier to predict here. But something has changed.

We already know that even in safe seats, voters tend to behave differently in local, devolved or European elections. This owes to the influence of local or subnational issues, or simply due to the desire to cast a protest vote, and can lead to a variety of results abnormal to that seen when the same electorate vote at a general election. These factors can be foreseen to some extent by electoral strategists, with election campaigns planned accordingly. The point is with safe seats is that they nearly always revert back to produce the same result at general elections, in spite of whatever may happen at the local, subnational or European level in the meantime.

Indyref blogWhat has surprised even the electoral strategists, however, has been the numbers of traditional Labour voters that are considering voting Yes on 18 September. A recent poll from YouGov put this number at 35%; an increase from 18% in the last month alone. This is despite the Labour Party explicitly positioning itself behind the No campaign and using its local political clout in both its many Westminster and Holyrood safe seats.

Just why it is that so many of its traditional voters are set to vote against the interests of its own party is for another blog on another day, but the question therefore emerges: if so many of Labour’s core Scottish voters are considering voting for independence, are they thus also voting for the sponsors of the independence movement itself, the Scottish National Party?

The evidence suggests that they are.

Averaging Scotland’s voting intention for the 2015 general election from YouGov’s 10 most recent polls, we see a complete reversal of what is happening elsewhere in the UK with Labour’s vote. Despite suffering its lowest share of the vote since the Second World War with 29% in 2010, the party has recovered to a trend currently holding nationally around 37%. In Scotland, however, whilst the Labour vote held remarkably well at 42% in 2010, our analysis shows that voting intention for the party now to have fallen to 31%.

The changes in voting intention here are remarkable – but the question remains; are they permanent?  If they are, it indicates that Labour may be set to inherit a very different voter base in Scotland, whatever the outcome of the referendum.