New Seat Details

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Wrexham 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
LAB	24,842	48.4%
CON	22,398	43.6%
Plaid	2,589	5.0%
LIB	1,193	2.3%
UKIP	327	0.6%
LAB Majority	2,444	4.8%

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.

Wrexham: Map

List of old seats forming part of Wrexham

Old seat: Clwyd South

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

Old seat: Clwyd South				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	Plaid Votes	MIN Votes	OTH Votes	Total Votes
Denbighshire	Corwen	1,826	Clwyd South and North Montgomeryshire	455	520	19	29	0	192	0	0	1,215
Denbighshire	Llandrillo	930	Clwyd South and North Montgomeryshire	229	243	10	14	0	99	0	0	595
Denbighshire	Llangollen	3,319	Clwyd South and North Montgomeryshire	836	896	41	51	0	314	0	0	2,138
Wrexham	Bronington	2,540	Wrexham	1,039	479	43	26	0	51	0	0	1,638
Wrexham	Brymbo	2,982	Wrexham	1,149	841	23	39	0	75	0	0	2,127
Wrexham	Bryn Cefn	1,482	Wrexham	363	663	36	23	0	47	0	0	1,132
Wrexham	Cefn	3,709	Clwyd South and North Montgomeryshire	884	1,576	43	60	0	106	0	0	2,669
Wrexham	Chirk North	1,811	Clwyd South and North Montgomeryshire	419	766	22	28	0	53	0	0	1,288
Wrexham	Chirk South	1,549	Clwyd South and North Montgomeryshire	374	598	14	22	0	47	0	0	1,055
Wrexham	Coedpoeth	3,482	Wrexham	803	1,282	43	58	0	277	0	0	2,463
Wrexham	Dyffryn Ceiriog / Ceiriog Valley	1,670	Clwyd South and North Montgomeryshire	487	505	16	25	0	99	0	0	1,132
Wrexham	Esclusham	2,023	Wrexham	554	762	27	35	0	73	0	0	1,451
Wrexham	Gwenfro	1,214	Wrexham	227	615	36	18	0	33	0	0	929
Wrexham	Johnstown	2,415	Clwyd South and North Montgomeryshire	660	905	31	43	0	79	0	0	1,718
Wrexham	Llangollen Rural	1,578	Clwyd South and North Montgomeryshire	447	532	16	25	0	56	0	0	1,076
Wrexham	Marchwiel	1,824	Wrexham	606	533	11	25	0	59	0	0	1,234
Wrexham	Minera	1,843	Wrexham	507	678	15	26	0	68	0	0	1,294
Wrexham	New Broughton	2,649	Wrexham	573	1,087	26	39	0	71	0	0	1,796
Wrexham	Overton	2,601	Wrexham	1,097	500	44	28	0	61	0	0	1,730
Wrexham	Pant	1,534	Clwyd South and North Montgomeryshire	395	744	20	26	0	50	0	0	1,235
Wrexham	Penycae	1,479	Clwyd South and North Montgomeryshire	403	659	17	25	0	47	0	0	1,151
Wrexham	Penycae and Ruabon South	1,898	Clwyd South and North Montgomeryshire	532	680	17	27	0	49	0	0	1,305
Wrexham	Plas Madoc	1,198	Clwyd South and North Montgomeryshire	242	733	6	17	0	23	0	0	1,021
Wrexham	Ponciau	3,467	Clwyd South and North Montgomeryshire; Wrexham	869	1,359	131	57	0	109	0	0	2,525
Wrexham	Ruabon	2,071	Clwyd South and North Montgomeryshire	495	848	22	34	0	152	0	0	1,551
	Total	53,094		14,645	19,004	729	800	0	2,290	0	0	37,468

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

Old seat: Wrexham

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

Old seat: Wrexham				Transfer-adjusted Results
District	Ward	Electorate 2017	New Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	Plaid Votes	MIN Votes	OTH Votes	Total Votes
Wrexham	Acton	2,184	Wrexham	567	921	41	0	0	41	0	0	1,570
Wrexham	Borras Park	1,628	Wrexham	664	435	42	0	0	27	0	0	1,168
Wrexham	Brynyffynnon	2,381	Wrexham	664	941	33	0	0	72	0	0	1,710
Wrexham	Cartrefle	1,646	Wrexham	490	631	18	0	0	43	0	0	1,182
Wrexham	Erddig	1,538	Wrexham	570	396	36	0	0	103	0	0	1,105
Wrexham	Garden Village	1,422	Wrexham	422	533	34	0	0	32	0	0	1,021
Wrexham	Gresford East and West	1,855	Wrexham	722	532	42	0	0	36	0	0	1,332
Wrexham	Grosvenor	1,849	Wrexham	478	678	53	0	0	119	0	0	1,328
Wrexham	Gwersyllt East and South	3,277	Wrexham	859	1,349	59	0	0	88	0	0	2,355
Wrexham	Gwersyllt North	1,990	Wrexham	489	835	15	0	0	90	0	0	1,429
Wrexham	Gwersyllt West	2,114	Wrexham	636	715	23	0	0	144	0	0	1,518
Wrexham	Hermitage	1,518	Wrexham	424	551	34	0	0	81	0	0	1,090
Wrexham	Holt	2,303	Wrexham	1,054	498	41	0	0	60	0	0	1,653
Wrexham	Little Acton	1,592	Wrexham	584	475	45	0	0	40	0	0	1,144
Wrexham	Llay	3,322	Wrexham	876	1,409	33	0	0	67	0	0	2,385
Wrexham	Maesydre	1,361	Wrexham	471	433	39	0	0	34	0	0	977
Wrexham	Marford and Hoseley	1,618	Wrexham	723	366	37	0	0	38	0	0	1,164
Wrexham	Offa	1,795	Wrexham	603	585	47	0	0	55	0	0	1,290
Wrexham	Queensway	1,857	Wrexham	427	805	9	0	0	93	0	0	1,334
Wrexham	Rhosnesni	2,590	Wrexham	889	722	66	0	0	183	0	0	1,860
Wrexham	Rossett	2,211	Wrexham	1,101	399	34	0	0	54	0	0	1,588
Wrexham	Smithfield	1,860	Wrexham	472	796	20	0	0	47	0	0	1,335
Wrexham	Stansty	1,456	Wrexham	383	600	28	0	0	35	0	0	1,046
Wrexham	Whitegate	1,919	Wrexham	446	797	22	0	0	113	0	0	1,378
Wrexham	Wynnstay	1,576	Wrexham	307	751	14	0	0	59	0	0	1,131
	Total	48,862		15,321	17,153	865	0	0	1,754	0	0	35,093

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

New seat: Wrexham

District	Ward	Electorate 2017	Old Seat	CON Votes	LAB Votes	LIB Votes	UKIP Votes	Green Votes	Plaid Votes	MIN Votes	OTH Votes	Total Votes
New seat: Wrexham
Wrexham	Acton	2,254	Wrexham	567	921	41	0	0	41	0	0	1,570
Wrexham	Borras Park	1,680	Wrexham	664	435	42	0	0	27	0	0	1,168
Wrexham	Bronington	2,376	Clwyd South	1,039	479	43	26	0	51	0	0	1,638
Wrexham	Brymbo	3,084	Clwyd South	1,149	841	23	39	0	75	0	0	2,127
Wrexham	Bryn Cefn	1,641	Clwyd South	363	663	36	23	0	47	0	0	1,132
Wrexham	Brynyffynnon	2,457	Wrexham	664	941	33	0	0	72	0	0	1,710
Wrexham	Cartrefle	1,699	Wrexham	490	631	18	0	0	43	0	0	1,182
Wrexham	Coedpoeth	3,572	Clwyd South	803	1,282	43	58	0	277	0	0	2,463
Wrexham	Erddig	1,587	Wrexham	570	396	36	0	0	103	0	0	1,105
Wrexham	Esclusham	2,105	Clwyd South	554	762	27	35	0	73	0	0	1,451
Wrexham	Garden Village	1,467	Wrexham	422	533	34	0	0	32	0	0	1,021
Wrexham	Gresford East and West	1,914	Wrexham	722	532	42	0	0	36	0	0	1,332
Wrexham	Grosvenor	1,908	Wrexham	478	678	53	0	0	119	0	0	1,328
Wrexham	Gwenfro	1,346	Clwyd South	227	615	36	18	0	33	0	0	929
Wrexham	Gwersyllt East and South	3,382	Wrexham	859	1,349	59	0	0	88	0	0	2,355
Wrexham	Gwersyllt North	2,053	Wrexham	489	835	15	0	0	90	0	0	1,429
Wrexham	Gwersyllt West	2,181	Wrexham	636	715	23	0	0	144	0	0	1,518
Wrexham	Hermitage	1,566	Wrexham	424	551	34	0	0	81	0	0	1,090
Wrexham	Holt	2,376	Wrexham	1,054	498	41	0	0	60	0	0	1,653
Wrexham	Little Acton	1,643	Wrexham	584	475	45	0	0	40	0	0	1,144
Wrexham	Llay	3,428	Wrexham	876	1,409	33	0	0	67	0	0	2,385
Wrexham	Maesydre	1,404	Wrexham	471	433	39	0	0	34	0	0	977
Wrexham	Marchwiel	1,790	Clwyd South	606	533	11	25	0	59	0	0	1,234
Wrexham	Marford and Hoseley	1,670	Wrexham	723	366	37	0	0	38	0	0	1,164
Wrexham	Minera	1,877	Clwyd South	507	678	15	26	0	68	0	0	1,294
Wrexham	New Broughton	2,606	Clwyd South	573	1,087	26	39	0	71	0	0	1,796
Wrexham	Offa	1,852	Wrexham	603	585	47	0	0	55	0	0	1,290
Wrexham	Overton	2,509	Clwyd South	1,097	500	44	28	0	61	0	0	1,730
Wrexham	Ponciau	672	Clwyd South	159	249	24	10	0	20	0	0	462
Wrexham	Queensway	1,916	Wrexham	427	805	9	0	0	93	0	0	1,334
Wrexham	Rhosnesni	2,673	Wrexham	889	722	66	0	0	183	0	0	1,860
Wrexham	Rossett	2,282	Wrexham	1,101	399	34	0	0	54	0	0	1,588
Wrexham	Smithfield	1,919	Wrexham	472	796	20	0	0	47	0	0	1,335
Wrexham	Stansty	1,502	Wrexham	383	600	28	0	0	35	0	0	1,046
Wrexham	Whitegate	1,980	Wrexham	446	797	22	0	0	113	0	0	1,378
Wrexham	Wynnstay	1,626	Wrexham	307	751	14	0	0	59	0	0	1,131
	Total	73,997		22,398	24,842	1,193	327	0	2,589	0	0	51,349

And these are the implied results for 2017 for the new seat of Wrexham. 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:	Ian Lucas (LAB)
County/Area:	Clwyd (Wales)
Electorate:	73,997
Turnout:	69.4%

Wrexham: New Boundaries 2018 Calculation

Wrexham: Overview

Introduction