New Seat Details - Northamptonshire South

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Northamptonshire South been in force at that time. The basic idea of the calculation is to look at the district council wards which make up the new seat, and estimate how they voted in 2017. This estimate is based on the recent local election results in those wards, with adjustments made to allow for different turnouts and different voting patterns for local and general elections.

In many cases, wards are divided between several old constituencies or between new constituencies. So the same ward may be shown more than once, but the electorate shown will reflect that ward sub-section.

Election results from a recent local election are given. This is usually the local election closest to 2015 from the period 2012-2015. For multiple-member wards, the votes shown are the sum of the votes cast for all candidates of each party. A negative number indicates candidate(s) elected unopposed.

Calculation method

There are two problems with using the raw (actual) local election results to imply general election results ward-by-ward. Firstly, turnout can be different between local and general elections, which means that the total number of local votes cast does not equal the number of votes cast in each old seat at the general election. To correct for this, we adjust the local votes to match the general election turnout. Each ward's result is scaled, whilst keeping constant the percentage support for each party, so that the total turnout adds up to the old seat's general election turnout. All wards in the old seat are assumed to have the same percentage turnout.

Party	Implied 2017 Votes	Implied 2017 Share
CON	34,661	65.2%
LAB	13,141	24.7%
LIB	2,851	5.4%
UKIP	1,157	2.2%
Green	1,104	2.1%
OTH	220	0.4%
CON Majority	21,520	40.5%

Secondly, even though we now have the correct number of votes in the old seat, the party totals will not match the general election result. Some parties do better at the local election than the general election, and others do vice versa. We call these strong and weak parties respectively. The next step is to transfer votes from strong parties to weak parties. This is done by taking votes proportionally away from strong parties and putting them in a transfer pool. For instance if a party got 12,500 local votes, but only 10,000 general election votes, it will lose 20% over all the wards. These votes in each ward will be put in the ward's transfer pool and allocated to the weak parties. Weak parties will get votes transferred to them in proportion to the votes they need over the old seat. For instance, if two weak parties need 4,000 and 1,000 votes respectively, the first party will get 80% of each ward's transfer pool and the second party will get 20% of each ward's transfer pool. The transfer of votes between parties is done using the Electoral Calculus Transition Model.

Northamptonshire South: Map

List of old seats forming part of Northamptonshire South

Old seat: Daventry

The table shows the transfer-adjusted results for each ward in the old seat of Daventry, as well as showing which new seat each ward is in.

Old seat: Daventry				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	NAT Votes	MIN Votes	OTH Votes	Total Votes
Daventry	Abbey North	4,731	Daventry and Lutterworth	2,194	1,413	304	147	48	0	0	0	4,106
Daventry	Abbey South	4,624	Daventry and Lutterworth	2,111	1,159	275	144	43	0	0	0	3,732
Daventry	Barby and Kilsby	3,559	Daventry and Lutterworth	2,088	596	483	53	34	0	0	0	3,254
Daventry	Braunston and Welton	1,936	Daventry and Lutterworth	755	542	71	21	16	0	0	0	1,405
Daventry	Brixworth	5,262	Daventry and Lutterworth	2,815	821	212	59	130	0	0	0	4,037
Daventry	Drayton	4,120	Daventry and Lutterworth	1,756	1,357	306	145	44	0	0	0	3,608
Daventry	Hill	3,942	Daventry and Lutterworth	1,859	1,142	252	123	40	0	0	0	3,416
Daventry	Long Buckby	5,046	Daventry and Lutterworth	2,473	996	292	129	52	0	0	0	3,942
Daventry	Moulton	3,722	Daventry and Lutterworth	1,680	521	156	38	88	0	0	0	2,483
Daventry	Ravensthorpe	1,905	Daventry and Lutterworth	961	245	109	47	17	0	0	0	1,379
Daventry	Spratton	3,027	Daventry and Lutterworth	1,811	416	159	84	25	0	0	0	2,495
Daventry	Walgrave	1,594	Daventry and Lutterworth	880	204	67	17	45	0	0	0	1,213
Daventry	Weedon	4,947	Northamptonshire South	2,456	709	360	118	42	0	0	0	3,685
Daventry	Welford	3,253	Daventry and Lutterworth	1,713	461	147	73	27	0	0	0	2,421
Daventry	Woodford	5,201	Northamptonshire South	2,604	895	186	63	123	0	0	0	3,871
Daventry	Yelvertoft	1,523	Daventry and Lutterworth	830	173	62	37	11	0	0	0	1,113
South Northamptonshire	Harpole and Grange	3,825	Northampton South	2,053	406	132	41	86	0	0	0	2,718
South Northamptonshire	Heyfords and Bugbrooke	3,649	Northamptonshire South	1,838	492	157	43	33	0	0	0	2,563
Wellingborough	Earls Barton	4,119	Daventry and Lutterworth	1,818	998	235	100	43	0	0	0	3,194
Wellingborough	Harrowden and Sywell	1,499	Daventry and Lutterworth	769	181	52	16	11	0	0	0	1,029
	Total	71,484		35,464	13,727	4,017	1,498	958	0	0	0	55,664

The full details of these calculations are given on the Daventry seat details page. Click on "Show workings".

Old seat: Northamptonshire South

The table shows the transfer-adjusted results for each ward in the old seat of Northamptonshire South, as well as showing which new seat each ward is in.

Old seat: Northamptonshire South				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	NAT Votes	MIN Votes	OTH Votes	Total Votes
Northampton	East Hunsbury	7,180	Northampton South	3,667	1,891	424	84	123	0	0	11	6,200
Northampton	Nene Valley	7,771	Northampton South	3,711	2,029	480	221	147	0	0	44	6,632
Northampton	Rushmills	501	Northampton South	195	135	29	13	9	0	0	0	381
Northampton	Upton	4,623	Northampton South	1,917	1,131	232	44	66	0	0	7	3,397
Northampton	West Hunsbury	3,301	Northampton South	1,608	829	196	40	54	0	0	8	2,735
South Northamptonshire	Astwell	1,598	Northamptonshire South	830	311	38	13	23	0	0	2	1,217
South Northamptonshire	Blakesley and Cote	2,895	Northamptonshire South	1,490	434	63	21	42	0	0	12	2,062
South Northamptonshire	Blisworth and Roade	3,534	Northamptonshire South	1,597	666	89	90	55	0	0	19	2,516
South Northamptonshire	Brackley East	3,439	Northamptonshire South	1,555	662	116	97	58	0	0	21	2,509
South Northamptonshire	Brackley South	3,259	Northamptonshire South	1,375	826	119	120	67	0	0	37	2,544
South Northamptonshire	Brackley West	3,373	Northamptonshire South	1,686	754	112	108	59	0	0	23	2,742
South Northamptonshire	Brafield and Yardley	3,389	Northamptonshire South	1,634	610	98	32	55	0	0	19	2,448
South Northamptonshire	Cosgrove and Grafton	1,607	Northamptonshire South	770	353	37	14	22	0	0	5	1,201
South Northamptonshire	Danvers and Wardoun	2,942	Northamptonshire South	1,582	446	64	25	41	0	0	8	2,166
South Northamptonshire	Deanshanger	3,206	Northamptonshire South	1,529	759	95	32	48	0	0	4	2,467
South Northamptonshire	Grange Park	3,036	Northampton South	1,739	698	117	28	51	0	0	5	2,638
South Northamptonshire	Hackleton	1,851	Northamptonshire South	943	297	48	16	24	0	0	2	1,330
South Northamptonshire	Kings Sutton	1,731	Northamptonshire South	708	467	54	16	27	0	0	2	1,274
South Northamptonshire	Kingthorn	1,493	Northamptonshire South	728	210	34	11	19	0	0	3	1,005
South Northamptonshire	Little Brook	1,667	Northamptonshire South	988	266	38	18	25	0	0	3	1,338
South Northamptonshire	Middleton Cheney	3,238	Northamptonshire South	1,560	549	91	32	45	0	0	14	2,291
South Northamptonshire	Old Stratford	1,557	Northamptonshire South	841	261	46	15	25	0	0	8	1,196
South Northamptonshire	Salcey	1,855	Northamptonshire South	925	331	53	21	27	0	0	5	1,362
South Northamptonshire	Silverstone	1,816	Northamptonshire South	892	318	42	15	26	0	0	8	1,301
South Northamptonshire	Steane	1,591	Northamptonshire South	847	263	36	15	23	0	0	4	1,188
South Northamptonshire	Tove	1,534	Northamptonshire South	772	231	32	31	21	0	0	3	1,090
South Northamptonshire	Towcester Brook	4,388	Northamptonshire South	1,680	1,010	469	134	83	0	0	7	3,383
South Northamptonshire	Towcester Mill	2,817	Northamptonshire South	1,208	550	308	31	49	0	0	5	2,151
South Northamptonshire	Washington	1,485	Northamptonshire South	757	209	27	11	19	0	0	4	1,027
South Northamptonshire	Whittlewood	1,760	Northamptonshire South	866	262	39	15	23	0	0	2	1,207
	Total	84,437		40,600	17,758	3,626	1,363	1,356	0	0	295	64,998

The full details of these calculations are given on the Northamptonshire South seat details page. Click on "Show workings".

New seat: Northamptonshire South

District	Ward	Electorate 2017	Old Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	NAT Votes	MIN Votes	OTH Votes	Total Votes
New seat: Northamptonshire South
Daventry	Weedon	4,987	Daventry	2,456	709	360	118	42	0	0	0	3,685
Daventry	Woodford	5,239	Daventry	2,604	895	186	63	123	0	0	0	3,871
South Northamptonshire	Astwell	1,605	Northamptonshire South	830	311	38	13	23	0	0	2	1,217
South Northamptonshire	Blakesley and Cote	2,721	Northamptonshire South	1,490	434	63	21	42	0	0	12	2,062
South Northamptonshire	Blisworth and Roade	3,319	Northamptonshire South	1,597	666	89	90	55	0	0	19	2,516
South Northamptonshire	Brackley East	3,310	Northamptonshire South	1,555	662	116	97	58	0	0	21	2,509
South Northamptonshire	Brackley South	3,357	Northamptonshire South	1,375	826	119	120	67	0	0	37	2,544
South Northamptonshire	Brackley West	3,618	Northamptonshire South	1,686	754	112	108	59	0	0	23	2,742
South Northamptonshire	Brafield and Yardley	3,230	Northamptonshire South	1,634	610	98	32	55	0	0	19	2,448
South Northamptonshire	Cosgrove and Grafton	1,584	Northamptonshire South	770	353	37	14	22	0	0	5	1,201
South Northamptonshire	Danvers and Wardoun	2,856	Northamptonshire South	1,582	446	64	25	41	0	0	8	2,166
South Northamptonshire	Deanshanger	3,255	Northamptonshire South	1,529	759	95	32	48	0	0	4	2,467
South Northamptonshire	Hackleton	1,754	Northamptonshire South	943	297	48	16	24	0	0	2	1,330
South Northamptonshire	Heyfords and Bugbrooke	3,468	Daventry	1,838	492	157	43	33	0	0	0	2,563
South Northamptonshire	Kings Sutton	1,680	Northamptonshire South	708	467	54	16	27	0	0	2	1,274
South Northamptonshire	Kingthorn	1,326	Northamptonshire South	728	210	34	11	19	0	0	3	1,005
South Northamptonshire	Little Brook	1,765	Northamptonshire South	988	266	38	18	25	0	0	3	1,338
South Northamptonshire	Middleton Cheney	3,021	Northamptonshire South	1,560	549	91	32	45	0	0	14	2,291
South Northamptonshire	Old Stratford	1,577	Northamptonshire South	841	261	46	15	25	0	0	8	1,196
South Northamptonshire	Salcey	1,797	Northamptonshire South	925	331	53	21	27	0	0	5	1,362
South Northamptonshire	Silverstone	1,716	Northamptonshire South	892	318	42	15	26	0	0	8	1,301
South Northamptonshire	Steane	1,569	Northamptonshire South	847	263	36	15	23	0	0	4	1,188
South Northamptonshire	Tove	1,439	Northamptonshire South	772	231	32	31	21	0	0	3	1,090
South Northamptonshire	Towcester Brook	4,464	Northamptonshire South	1,680	1,010	469	134	83	0	0	7	3,383
South Northamptonshire	Towcester Mill	2,838	Northamptonshire South	1,208	550	308	31	49	0	0	5	2,151
South Northamptonshire	Washington	1,356	Northamptonshire South	757	209	27	11	19	0	0	4	1,027
South Northamptonshire	Whittlewood	1,593	Northamptonshire South	866	262	39	15	23	0	0	2	1,207
	Total	70,444		34,661	13,141	2,851	1,157	1,104	0	0	220	53,134

And these are the implied results for 2017 for the new seat of Northamptonshire South. Please note that the wards used are those of 2015 in order to be consistent with those used by the Boundary Commissions.

Implied MP at 2017:	Andrea Leadsom (CON)
County/Area:	Northamptonshire (East Midlands)
Electorate:	70,444
Turnout:	75.4%

Northamptonshire South: New Boundaries 2018 Calculation

Northamptonshire South: Overview

Introduction