UK Election Math: What are the Odds of a Hung Parliament?
The above chart is from Electoral Calculus. Prediction based on opinion polls from 25 Oct 2019 to 04 Nov 2019, sampling 15,917 people.
Tory Starting Point
- 650 Seats
- Expect Sin Fein to pickup one seat. If Sin Fein does not sit, and it's likely they don't sit, Parliament will have 642 MPs.
- The Speaker and 3 deputies do not vote and are considered non-partisan.
- 650-8-4 - 638.
- A majority is over half. Thus 638/2 + 1 = 320
If the speaker and deputies do count, then the majority is 322.
DUP was part of Theresa May's fragile majority but will not be part of Johnson's.
Tory Starting Point 270
- Assume the Scottish National Party wipes out 13 Tory seats,
- Assume the Liberal Democrats alliance works and that tips 6 more seats.
- One seat from Plaid Cymru seems headed to the Tories.
The net result of those subtractions is 270. Thus the Tories need to pick up 52 seats just to have a bare majority. How likely is that?
Battle for the Soul of Great Britain
In Battle for the Soul of Great Britain I discussed London and Wales.
Today, YouGov released polls for every region. Let's go over them all.
Regional Voting Intention Wales
Wales is divided into forty Parliamentary constituencies. After the General Election of June 2017 and a by-election in August 2019, 28 are represented by Labour MPs, 7 by Conservative MPs, 4 by Plaid Cymru MPs, and one by a Liberal Democrat MP.
On a 49-34 percentage lead in votes, Labour held a 28-7 seat advantage over the Tories.
Expect a Tory pickup of 8 seats.
North East - You Gov
Regional Voting Intention North East
The region of [North East England](https://en.wikipedia.org/wiki/List_of_Parliamentary_constituencies_in_the_North_East_(region/%29) is divided into 29 parliamentary constituencies which is made up of 19 Borough Constituencies and 10 County Constituencies. Since the General Election of June 2017, 26 are represented by Labour MPs and 3 by Conservative MPs.
The Brexit Party could be a killer here. If they stood aside, I would expect the Tories to win about 16 seats. That's a pickup of 13.
The latest poll suggests a pickup of about 6-9 seats for the Tory Party. Call it 6.
North West - You Gov
Regional Voting Intention North West
The region of [North West England](https://en.wikipedia.org/wiki/List_of_Parliamentary_constituencies_in_the_North_West_(region/) is divided into 75 parliamentary constituencies
which is made up of 39 Borough Constituencies and 36 County Constituencies. Since the General Election of June 2017, 20 are represented by Conservative MPs, 54 by Labour MPs, and 1 by Liberal Democrat MPs.
With a 55-33 margin in favor of Labour over the Tories, the Tories managed 20 out of 75 seats.
The Tories are now leading 36-30. A pickup of 20 seats (40 Tory, 35 Other), seems reasonable.
The Brexit Party may cost additional pickups, but not as many as in the North East given the Tory majority.
Scotland Current MP Makeup
Regional Voting Intent Scotland
Labour will be wiped out in Scotland. With these numbers it is a bit unreasonable to expect a total blowout where conservatives lose every seat. Let's assume they hold 4.
Regional Voting Intention Northshire and Humber
The region of [Yorkshire and the Humber](https://en.wikipedia.org/wiki/List_of_Parliamentary_constituencies_in_Yorkshire_and_the_Humber_(region/) is divided into 54 parliamentary constituencies which is made up of 25 Borough Constituencies and 29 County Constituencies. As of September 2019 17 are represented by Conservative MPs, 35 by Labour MPs, 1 Liberal Democrat MP and 1 Independent MP.
That makeup was with a 49-34 advantage of Labour over the Tories.
I suggest a Tory pickup of 15 or more. Call it 15.
Regional Voting Intention East Midlands
The region of [East Midlands](https://en.wikipedia.org/wiki/List_of_Parliamentary_constituencies_in_the_East_Midlands_(region/) is divided into 46 parliamentary constituencies which is made up of 12 Borough Constituencies and 34 County Constituencies. Since the General Election of June 2017, 31 are represented by Conservative MPs and 15 by Labour MPs.
With a 51-41 (10-point) lead, the Tories had a 31-15 seat advantage. The Tory lead is now 13 points.
Expect a pickup of 5-8 seats. Call it 6.
Regional Voting Intention West Midlands
The ceremonial county of [West Midlands](https://en.wikipedia.org/wiki/List_of_Parliamentary_constituencies_in_the_West_Midlands_(county/), England is divided into 28 parliamentary constituencies, each of which elect one Member of Parliament (MP) to the House of Commons.
Despite a 49-43 lead over Labour in 2017, Labour held 20 seats with the Tories 8.
With a 43-23 lead, expect a reversal. Tories +12.
Regional Voting Intention East of England
The region of [East of England](https://en.wikipedia.org/wiki/List_of_Parliamentary_constituencies_in_the_East_of_England_(region/) is divided into 58 parliamentary constituencies which is made up of 16 Borough Constituencies and 42 County Constituencies. Since the General Election of June 2017, 50 are represented by Conservative MPs, 7 by Labour MPs, and 1 by Liberal Democrat MPs.
On a 55-33 vote in 2017, the Tories held 50 MPs with Labour only 7.
Assume a modest gain of 2 but with Labour losing a handful more to the Liberal Democrats.
Regional Voting Intention South East
The region of [South East](https://en.wikipedia.org/wiki/List_of_Parliamentary_constituencies_in_the_South_East_(region/) is divided into 84 parliamentary constituencies which is made up of 23 Borough Constituencies and 61 County Constituencies. 60 are represented by Conservative MPs, 11 by Independent MPs, 8 by Labour MPs, 3 by Liberal Democrat MPs, 1 by Green MPs and the Speaker of the House of Commons.
On a 54-29 vote percentage the Tories held 60 of 81 seats.
They rate to pick up 5-8. Call it +5. Labour rates to get smashed to 0-2 seats.
Regional Voting Intention Greater London
The region of Greater London, including the City of London, is divided into 73 parliamentary constituencies which are sub-classified as borough constituencies, affecting the type of electoral officer and level of expenses permitted. As of September 2019, 46 are represented by Labour MPs, 19 by Conservative MPs, 4 by Liberal Democrat MPs, 2 by The Independent Group for Change, and 2 are held by independents.
On a 55-33 voting lead (22 points) over the Tories, Labour held an edge in seats of 46-19.
The lead is now down to 10 points. Expect a Tory pickup 8 seats.
Regional Voting Intention South West
The region of South West England has, since the 2010 general election, 55 parliamentary constituencies which is made up of 15 Borough Constituencies and 40 County Constituencies. In the 2017 general election, the Conservatives remained, by far, the largest party with 47 seats, though losing three to Labour, who won 7, and one to the Liberal Democrats, who won 1.
On a 51-29 lead in votes (22 points) the Tories held a seat advantage over Labour by a 47-7 margin. The lead is now down to 20 not over Labour, but over the Liberal Democrats.
This is another region in which the Brexit Party might hurt the Tories significantly.
I expect a loss of about 5 seats but also with Labour getting clobbered by the Liberal Democrats.
Expected Gains vs Starting Scenario
- London: +8
- Wales: +8
- North East: +6
- North West: +20
- Scotland: +4
- Yorkshire and Humber: +15
- East Midlands: +6
- West Midlands: +12
- East of England: +2
- South East: +5
- South West: -5
That is a total of +81 seats.
Allowing 8 Sin Fein candidates who will not sit, plus the nonvoting speaker and three deputies, the parliament effective size is 638 as explained above, making the majority 320.
From the starting point of 270, the Tories are up to 351 by my estimation. That's a surplus of 31 over the required 320.
If so, the Tory majority based on current polls would be 351 - 287 = 64.
That's a very conservative number actually.
On the same polls Electoral Calculus said "Current Prediction: Conservative majority 96".
Electoral Calculus gave the Tories 373 seats, I estimated only 351, a huge 22 seats more cautious.
The above charts from the Nov 8 YouGov article Regional voting intentions show both main parties down everywhere, with Labour hit particularly hard.
- All of the polls are from one source: You Gov
- Most of the polls are a bit out of date, but not radically so.
Best Case Scenario
The best case scenario could easily be above 351.
Let's assume YouGov is way off, possibly even low.
Expected Gains Range vs Starting Scenario
- London: +5 to +10.
- Wales: +6 to +10.
- North East: +3 to +8.
- North West: +15 to +22.
- Scotland: +0 to +6.
- Yorkshire and Humber: +10 to +20.
- East Midlands: +3 to +9.
- West Midlands: +9 to +16.
- East of England: +0 to +4.
- South East: +3 to +7.
- South West: -7 to +0.
- 37 + 270 = 307.
- 112 +270 = 382.
The first is a hung parliament.
The second is the mother of all blowouts.
And it is not all that unlikely.
Note that Electoral Calculus expects 373 seats. My blowout number is just 9 seats more that the Electoral Calculus base assumption.
Probabilities Based on Current Polls
- Outright Labour Win: 2%
- Hung Parliament: 23%
- Small Majority (by 1-6 seats): 15%
- Medium Majority (by 7-20 seats): 25%
- Big Majority (by 21-40 seats): 20%
- Blowout (over 40 seats): 15%
Divide and Concur
If these polls are remotely close, and I believe they are, Johnson's strategy of splitting Labour and the Liberal democrats is working precisely as planned.
Mike "Mish" Shedlock