In the meantime there is a United Kingdom general election in May 2015.
The last election, in May 2010, gave the following result:
- Conservative - 306 (including 1 Deputy Speaker)
- Labour - 258 (including 2 Deputy Speakers)
- Liberal Democrat - 57
- Democratic Unionist Party - 8
- Scottish National Party - 6
- Sinn Féin - 5
- Plaid Cymru - 3
- Social Democratic & Labour Party - 3
- Green Party of England & Wales - 1
- Alliance Party of Northern Ireland - 1
- Independent Unionist - 1
- The Speaker - 1
The Speaker and Deputy Speakers do not vote - bringing the number of voting MPs down from 650 to 646. But the Sinn Féin MPs don't take their seats, so there are 641 voting MPs. To have an overall majority thus needs 321 MPs.
The Conservatives and Liberal Democrats had 362 MPs between them, while Labour and the Liberal Democrats just had 313.
Now look at the Scottish result:
- Labour - 41
- Liberal Democrat - 11
- Scottish National Party - 6
- Conservative - 1
That is 59 MPs. Hence, if Scotland voted to leave, then there would be just 591 MPs in the remaining United Kingdom (often shortened to rUK). Using the logic above, with 9 non-voting MPs there would be 582 voting MPs, and hence to have an overall majority of 2 a party or coalition would need 292 MPs.
If we look at the rUK result, we have:
- Conservative - 305 (including 1 Deputy Speaker)
- Labour - 217 (including 2 Deputy Speakers)
- Liberal Democrat - 46
- Democratic Unionist Party - 8
- Sinn Féin - 5
- Plaid Cymru - 3
- Social Democratic & Labour Party - 3
- Green Party of England & Wales - 1
- Alliance Party of Northern Ireland - 1
- Independent Unionist - 1
- The Speaker - 1
As we can see, the Conservatives would easily pass that 292 MPs threshhold, and thus would have been able to form a majority Government.
Suppose that two things had happened:
- Prior to the 2010 election, Scotland had voted for independence, but it had not happened by the time of the election
- In rUK, Labour won an extra 10 seats from the Conservatives
In those circumstances, the Conservatives and Liberal Democrats would have 352 MPs between them, while Labour and the Liberal Democrats would have 323. And in rUK, the Conservatives would have 294 MPs.
Coalition forming would have been interesting. The Liberal Democrats would have had the choice to back either main party, knowing that once Scotland had become independent and the MPs representing Scottish constituencies left the House of Commons, there would be a Conservative majority Government. So, which way to go? Form a short-lived Labour/Liberal Democrat Government, knowing it'll be out of office the following year, or form a Conservative/Liberal Democrat one, knowing they'll be dumped by the Conservatives the following year?
Now, instead of it being 10 seats switching from the Conservatives to Labour, imagine it was 20 - hence the Conservatives and Liberal Democrats would have 342 MPs between them, while it'd be 333 for Labour and the Liberal Democrats. But for rUK, the Conservatives would have 284 MPs, while Labour and the Liberal Democrats would have 281. Seems like a similar situation as the previous paragraph - but the Conservatives would not have an overall majority of the rUK seats. Hence for a majority Government to be formed in rUK, it would have to be the Conservatives and the Liberal Democrats together.
This creates an interesting set of possible outcomes:
- From the start the Liberal Democrats enter Government with the Conservatives, knowing that it'll have a majority both before and after Scotland leaves the UK
- At the start the Liberal Democrats enter Government with Labour, but once Scotland leaves the UK, that Government loses its majority and the Liberal Democrats switch sides to form a Government with the Conservatives
- At the start the Liberal Democrats enter Government with Labour, and once Scotland leaves the UK, that Government loses its majority, and looks around minor parties for the extra 11 MP they need (note that they would need the Democratic Unionist Party, as the other minor parties and independent only have 9 MPs between them)
- At the start Labour and the Liberal Democrats sit down with minor parties to get the onboard from Day One, and a Labour/Liberal Democrat Government backed up by confidence-and-supply deals takes office, although it doesn't need those deals while Scotland is still in the UK
Next, consider 31 seats switching from the Conservatives to Labour. In this case, across the UK, the Conservatives and Liberal Democrats would have 331 MPs between them, while Labour and the Liberal Democrats have 334 MPs between them. And for rUK, the Conservatives and Liberal Democrats would have 319 MPs between them, with Labour and the Liberal Democrats having 292. Hence the Liberal Democrats could form a majority Government with either party, with or without Scotland.
So far, we have scenarios where the Liberal Democrats would have to plan carefully for a Government that could survive the loss of Scotland, or simply being temporary coalition partners prior to a majority Conservative Government running rUK. But the Liberal Democrats might not always be as powerful. What if they had a severe collapse?
Could we have the situation where a majority Labour Government would exist in the UK, but a majority Conservative one in rUK?
We need the following circumstances:
- The Conservatives have 292 seats or more in rUK
- Labour has 321 seats or more in the UK
There are 13 voting MPs from Northern Ireland and Plaid Cymru are reasonably safe in Dwyfor Meirionnydd, whilst being the party most likely to win Ceredigion from the Liberal Democrats.
So that gives us at least 15 minor party seats in rUK. If the Conservatives have at least 292 seats, there are 15 for minor parties, then there are at most 275 for Labour and the Liberal Democrats combined.
Assuming no there are no Liberal Democrat MPs in rUK, then Labour would need 46 of Scotland's MPs to have an overall majority in the UK as a whole. And for each Liberal Democrat MP in rUK, the number of Scottish constituencies Labour would have to win would increase by 1.
While it is possible, it would rely on a rare set of circumstances. Gone are the days when you just have Conservative, Labour and Liberal MPs. It is much more likely that a Labour Government relying on Scottish seats would be forced to seek a coalition partner or confidence-and-supply deals.
But there is an issue - would Scotland leaving the UK mean that Scottish MPs would have to leave the House of Commons?
We can look back at the Irish example of 1922. On 31 March, Parliament passed the Irish Free State (Agreement) Act 1922, and the following day an Order-in-Council provided full devolution to the Provisional Government of Southern Ireland (the devolved part of the UK that is equivalent to the modern day Republic of Ireland).
One of its provisions stated:
(4) No writ shall be issued after the passing of this Act for the election of a member to serve in the Commons House of Parliament for a constituency in Ireland other than a constituency in Northern Ireland.
But from April, while Southern Ireland was de jure a devolved part of the UK, it was de facto an independent nation. In December 1918, there had been a general election, and the result for what became Southern Ireland was:
- Sinn Féin - 70
- Irish Unionist - 2
- Irish Nationalist - 2
- Independent Unionist - 1
The Sinn Féin MPs did not take their seats, so this left 5 MPs (Edward Kelly, Nationalist, Donegal East; Maurice Dockrell, Unionist, Dublin Rathmines; Arthur Samuels, Unionist, Dublin University; Robert Woods, Independent Unionist, Dublin University; William Redmond, Nationalist, Waterford City) who were sitting in a House of Commons which no longer legislated for their constituencies.
In the autumn of 1922 there is a sequence of events:
- October 19 - the meeting at the Carlton Club from which the 1922 Committee does not take its name, voting to leave the Government, leading to Austen Chamberlain, then the Lord Privy Seal, resigning as leader of the Conservative MPs
- October 23 - Andrew Bonar Law becomes Conservative leader, David Lloyd George resigns as Prime Minister, with Bonar Law replacing him and forming a Conservative Government
- October 26 - Parliament is dissolved
- November 15 - General election. Although Southern Ireland is still legally part of the UK, no writs are issued for there
- December 6 - Irish Free State created
- December 7 - Northern Ireland secedes from the Irish Free State
The timings of the creation of the Irish Free State and the election are a coincidence.
But what is the lesson here? Presumably if Scotland votes for independence, then in the various Acts of Parliament, there'll be one stating that no writ will be issued for a Scottish constituency. But would this be before or after the 2015 election - i.e. would it be framed in such a way that only rUK goes to the polls and Scotland has 10 months of being part of the UK but with no MPs?
And if after the election, would it explicitly remove the Scottish MPs on Independence Day, or put them in 4 years of limbo - sitting in a Parliament that has no authority over their constituencies. But is this different from Kelly, Dockrell, Samuels, Woods and Redmond spending 6 months in this situation?
For the current Government (or at least the Conservative part of it), it would be in their best interests to have an Act with such a provision on the statute book this side of the 2015 election. While if Labour win the next election (or lead a coalition) then it would be in their best interests to allow Scottish MPs to remain until Parliament is dissolved in the spring of 2020, and for there to be natural wastage (i.e. as Scottish MPs die or resign, their seats remain unfilled).