New Seat Details - Bramhall and Wilmslow

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Bramhall and Wilmslow 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	29,587	49.9%
LAB	15,763	26.6%
LIB	12,622	21.3%
Green	692	1.2%
OTH	490	0.8%
UKIP	197	0.3%
CON Majority	13,824	23.3%

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.

Bramhall and Wilmslow: Map

List of old seats forming part of Bramhall and Wilmslow

Old seat: Cheadle

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

Old seat: Cheadle				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
Stockport	Bramhall North	10,263	Bramhall and Wilmslow	4,238	963	2,707	0	0	0	0	0	7,908
Stockport	Bramhall South and Woodford	9,589	Bramhall and Wilmslow	3,943	682	2,552	0	0	0	0	0	7,177
Stockport	Cheadle and Gatley	11,434	Stockport West and Cheadle	3,580	1,874	3,334	0	0	0	0	0	8,788
Stockport	Cheadle Hulme North	9,682	Stockport West and Cheadle	2,767	1,866	3,035	0	0	0	0	0	7,668
Stockport	Cheadle Hulme South	10,256	Stockport West and Cheadle	3,571	1,305	3,125	0	0	0	0	0	8,001
Stockport	Heald Green	9,664	Stockport West and Cheadle	3,195	1,944	2,416	0	0	0	0	0	7,555
Stockport	Stepping Hill	9,641	Bramhall and Wilmslow	3,036	1,783	2,655	0	0	0	0	0	7,474
	Total	70,529		24,330	10,417	19,824	0	0	0	0	0	54,571

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

Old seat: Hazel Grove

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

Old seat: Hazel Grove				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
Stockport	Bredbury and Woodley	10,358	Marple and Hyde	3,106	1,766	2,738	0	87	0	0	0	7,697
Stockport	Bredbury Green and Romiley	10,615	Marple and Hyde	3,398	1,862	2,474	0	93	0	0	0	7,827
Stockport	Hazel Grove	10,488	Bramhall and Wilmslow	3,847	1,488	2,459	0	91	0	0	0	7,885
Stockport	Marple North	9,622	Marple and Hyde	3,442	943	2,268	0	84	0	0	0	6,737
Stockport	Marple South	9,619	Marple and Hyde	3,280	1,068	2,107	0	81	0	0	0	6,536
Stockport	Offerton	10,016	Stockport East and Denton	2,975	1,908	2,488	0	80	0	0	0	7,451
	Total	60,718		20,048	9,035	14,534	0	516	0	0	0	44,133

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

Old seat: Stockport

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

Old seat: Stockport				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
Stockport	Brinnington and Central	9,611	Stockport East and Denton	1,344	5,334	203	198	97	0	0	0	7,176
Stockport	Davenport and Cale Green	10,249	Bramhall and Wilmslow	2,003	4,635	361	197	103	0	0	0	7,299
Stockport	Edgeley and Cheadle Heath	10,005	Stockport West and Cheadle	1,723	4,635	312	183	95	0	0	0	6,948
Stockport	Heatons North	10,269	Stockport West and Cheadle	2,534	3,623	241	150	94	0	0	0	6,642
Stockport	Heatons South	10,551	Stockport West and Cheadle	2,307	3,932	288	149	105	0	0	0	6,781
Stockport	Manor	9,979	Stockport East and Denton	1,894	4,123	373	210	96	0	0	0	6,696
	Total	60,664		11,805	26,282	1,778	1,087	590	0	0	0	41,542

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

Old seat: Tatton

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

Old seat: Tatton				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
Cheshire East	Alderley Edge	3,425	Bramhall and Wilmslow	1,746	654	256	0	43	0	0	78	2,777
Cheshire East	Chelford	3,169	Macclesfield	1,577	406	269	0	65	0	0	32	2,349
Cheshire East	Handforth	6,709	Bramhall and Wilmslow	2,517	2,030	507	0	87	0	0	146	5,287
Cheshire East	High Legh	3,349	Altrincham and Knutsford	1,807	469	156	0	78	0	0	22	2,532
Cheshire East	Knutsford	9,902	Altrincham and Knutsford	4,888	1,895	616	0	109	0	0	173	7,681
Cheshire East	Mobberley	3,357	Altrincham and Knutsford	1,705	469	407	0	28	0	0	46	2,655
Cheshire East	Wilmslow Dean Row	3,294	Bramhall and Wilmslow	1,609	657	223	0	40	0	0	65	2,594
Cheshire East	Wilmslow East	2,880	Bramhall and Wilmslow	1,523	492	200	0	92	0	0	59	2,366
Cheshire East	Wilmslow Lacey Green	3,304	Bramhall and Wilmslow	1,559	1,037	209	0	40	0	0	25	2,870
Cheshire East	Wilmslow West and Chorley	7,442	Bramhall and Wilmslow	3,566	1,342	493	0	196	0	0	117	5,714
Cheshire West and Chester	Marbury	9,496	Weaver Vale	3,775	2,348	632	0	187	0	0	90	7,032
Cheshire West and Chester	Shakerley	3,431	Eddisbury	1,433	710	227	0	27	0	0	36	2,433
Cheshire West and Chester	Witton and Rudheath	3,582	Eddisbury	1,060	1,468	238	0	31	0	0	30	2,827
	Total	63,340		28,765	13,977	4,433	0	1,023	0	0	919	49,117

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

New seat: Bramhall and Wilmslow

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: Bramhall and Wilmslow
Cheshire East	Alderley Edge	3,838	Tatton	1,746	654	256	0	43	0	0	78	2,777
Cheshire East	Handforth	7,305	Tatton	2,517	2,030	507	0	87	0	0	146	5,287
Cheshire East	Wilmslow Dean Row	3,585	Tatton	1,609	657	223	0	40	0	0	65	2,594
Cheshire East	Wilmslow East	3,269	Tatton	1,523	492	200	0	92	0	0	59	2,366
Cheshire East	Wilmslow Lacey Green	3,964	Tatton	1,559	1,037	209	0	40	0	0	25	2,870
Cheshire East	Wilmslow West and Chorley	7,897	Tatton	3,566	1,342	493	0	196	0	0	117	5,714
Stockport	Bramhall North	10,547	Cheadle	4,238	963	2,707	0	0	0	0	0	7,908
Stockport	Bramhall South and Woodford	9,571	Cheadle	3,943	682	2,552	0	0	0	0	0	7,177
Stockport	Davenport and Cale Green	11,145	Stockport	2,003	4,635	361	197	103	0	0	0	7,299
Stockport	Hazel Grove	11,199	Hazel Grove	3,847	1,488	2,459	0	91	0	0	0	7,885
Stockport	Stepping Hill	9,968	Cheadle	3,036	1,783	2,655	0	0	0	0	0	7,474
	Total	82,288		29,587	15,763	12,622	197	692	0	0	490	59,351

And these are the implied results for 2017 for the new seat of Bramhall and Wilmslow. 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:	Unknown (new seat) (CON)
County/Area:	Eastern Manchester (North West)
Electorate:	82,288
Turnout:	72.1%

Bramhall and Wilmslow: New Boundaries 2018 Calculation

Bramhall and Wilmslow: Overview

Introduction