New Seat Details - Conwy and Colwyn

This page shows the detail of the calculations performed to estimate the general election result for 2017 had the new boundaries for Conwy and Colwyn 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	27,049	48.2%
LAB	23,264	41.4%
Plaid	4,252	7.6%
LIB	1,592	2.8%
CON Majority	3,785	6.7%

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.

Conwy and Colwyn: Map

List of old seats forming part of Conwy and Colwyn

Old seat: Aberconwy

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

Old seat: Aberconwy				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
Conwy	Betws-y-Coed	932	Gwynedd	323	244	11	0	0	125	0	0	703
Conwy	Bryn	1,349	Anglesey and Bangor	340	558	21	0	0	124	0	0	1,043
Conwy	Caerhun	1,609	Gwynedd	640	352	14	0	0	131	0	0	1,137
Conwy	Capelulo	1,179	Anglesey and Bangor	398	348	41	0	0	59	0	0	846
Conwy	Conwy	3,227	Conwy and Colwyn	951	1,126	42	0	0	204	0	0	2,323
Conwy	Craig-y-Don	2,801	Conwy and Colwyn	955	694	32	0	0	271	0	0	1,952
Conwy	Crwst	1,583	Gwynedd	470	490	58	0	0	195	0	0	1,213
Conwy	Deganwy	3,235	Conwy and Colwyn	1,365	677	94	0	0	106	0	0	2,242
Conwy	Eglwysbach	1,195	Gwynedd	387	298	11	0	0	170	0	0	866
Conwy	Gogarth	2,829	Conwy and Colwyn	985	990	43	0	0	175	0	0	2,193
Conwy	Gower	887	Gwynedd	242	294	12	0	0	135	0	0	683
Conwy	Llansanffraid	1,807	Conwy and Colwyn	651	478	45	0	0	83	0	0	1,257
Conwy	Marl	3,500	Conwy and Colwyn	995	916	162	0	0	137	0	0	2,210
Conwy	Mostyn (Conwy)	2,751	Conwy and Colwyn	817	949	112	0	0	120	0	0	1,998
Conwy	Pandy	1,433	Anglesey and Bangor	360	521	26	0	0	126	0	0	1,033
Conwy	Pant-yr-afon / Penmaenan	2,119	Anglesey and Bangor	552	954	29	0	0	102	0	0	1,637
Conwy	Penrhyn	3,784	Conwy and Colwyn	1,572	1,001	65	0	0	152	0	0	2,790
Conwy	Pensarn	2,075	Conwy and Colwyn	633	671	33	0	0	275	0	0	1,612
Conwy	Trefriw	1,022	Gwynedd	283	282	15	0	0	128	0	0	708
Conwy	Tudno	3,606	Conwy and Colwyn	1,051	1,577	65	0	0	173	0	0	2,866
Conwy	Uwch Conwy	1,230	Gwynedd	367	283	12	0	0	179	0	0	841
	Total	44,153		14,337	13,703	943	0	0	3,170	0	0	32,153

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

Old seat: Clwyd West

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

Old seat: Clwyd West				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
Conwy	Abergele Pensarn	1,905	Conwy and Colwyn	491	802	14	0	0	44	0	0	1,351
Conwy	Betws yn Rhos	1,626	Conwy and Colwyn	516	411	13	0	0	222	0	0	1,162
Conwy	Colwyn	3,288	Conwy and Colwyn	1,130	1,039	122	0	0	237	0	0	2,528
Conwy	Eirias	2,749	Conwy and Colwyn	853	824	118	0	0	164	0	0	1,959
Conwy	Gele	3,784	Conwy and Colwyn	1,269	931	34	0	0	304	0	0	2,538
Conwy	Glyn	2,935	Conwy and Colwyn	746	1,220	58	0	0	357	0	0	2,381
Conwy	Kinmel Bay	4,506	Conwy and Colwyn	1,832	1,347	43	0	0	133	0	0	3,355
Conwy	Llanddulas	1,323	Conwy and Colwyn	394	347	52	0	0	50	0	0	843
Conwy	Llandrillo yn Rhos	6,032	Conwy and Colwyn	2,374	1,411	69	0	0	320	0	0	4,174
Conwy	Llangernyw	1,147	Gwynedd	343	281	8	0	0	162	0	0	794
Conwy	Llansannan	1,470	Gwynedd	441	374	11	0	0	207	0	0	1,033
Conwy	Llysfaen	1,862	Conwy and Colwyn	633	763	21	0	0	90	0	0	1,507
Conwy	Mochdre	1,458	Conwy and Colwyn	346	640	16	0	0	59	0	0	1,061
Conwy	Pentre Mawr	2,747	Conwy and Colwyn	1,097	676	79	0	0	86	0	0	1,938
Conwy	Rhiw	4,909	Conwy and Colwyn	1,922	1,312	170	0	0	252	0	0	3,656
Conwy	Towyn	1,842	Conwy and Colwyn	780	472	16	0	0	45	0	0	1,313
Conwy	Uwchaled	1,124	Gwynedd	389	295	10	0	0	71	0	0	765
Denbighshire	Efenechtyd	1,316	Clwyd South and North Montgomeryshire	398	325	14	0	0	179	0	0	916
Denbighshire	Llanarmon-yn-Ial / Llandegla	1,978	Clwyd South and North Montgomeryshire	825	381	23	0	0	99	0	0	1,328
Denbighshire	Llanbedr Dyffryn Clwyd / Llangynhafal	1,218	Clwyd South and North Montgomeryshire	527	210	8	0	0	51	0	0	796
Denbighshire	Llanfair Dyffryn Clwyd / Gwyddelwern	1,793	Clwyd South and North Montgomeryshire	644	470	21	0	0	113	0	0	1,248
Denbighshire	Llanrhaeadr-yng-Nghinmeirch	1,478	Clwyd South and North Montgomeryshire	448	360	12	0	0	204	0	0	1,024
Denbighshire	Ruthin	4,372	Clwyd South and North Montgomeryshire	1,143	1,214	163	0	0	468	0	0	2,988
	Total	56,862		19,541	16,105	1,095	0	0	3,917	0	0	40,658

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

Old seat: Vale of Clwyd

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

Old seat: Vale of Clwyd				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	Bodelwyddan	1,583	Conwy and Colwyn	523	607	13	0	0	34	0	0	1,177
Denbighshire	Denbigh Central	1,567	Clwyd South and North Montgomeryshire	487	538	18	0	0	117	0	0	1,160
Denbighshire	Denbigh Lower	3,575	Clwyd South and North Montgomeryshire	1,132	995	92	0	0	256	0	0	2,475
Denbighshire	Denbigh Upper / Henllan	2,371	Clwyd South and North Montgomeryshire	529	1,073	47	0	0	81	0	0	1,730
Denbighshire	Dyserth	1,905	Rhuddlan and Flint	681	518	36	0	0	44	0	0	1,279
Denbighshire	Llandyrnog	1,652	Clwyd South and North Montgomeryshire	568	458	28	0	0	106	0	0	1,160
Denbighshire	Prestatyn Central	2,814	Rhuddlan and Flint	915	933	25	0	0	43	0	0	1,916
Denbighshire	Prestatyn East	3,219	Rhuddlan and Flint	1,203	939	20	0	0	53	0	0	2,215
Denbighshire	Prestatyn Meliden	1,572	Rhuddlan and Flint	573	502	13	0	0	30	0	0	1,118
Denbighshire	Prestatyn North	4,691	Rhuddlan and Flint	1,306	1,697	44	0	0	48	0	0	3,095
Denbighshire	Prestatyn South West	2,848	Rhuddlan and Flint	862	971	19	0	0	28	0	0	1,880
Denbighshire	Rhuddlan	2,851	Rhuddlan and Flint	1,101	705	46	0	0	123	0	0	1,975
Denbighshire	Rhyl East	3,684	Rhuddlan and Flint	1,034	1,207	25	0	0	29	0	0	2,295
Denbighshire	Rhyl South	2,948	Rhuddlan and Flint	837	1,035	27	0	0	96	0	0	1,995
Denbighshire	Rhyl South East	6,007	Rhuddlan and Flint	1,584	2,305	73	0	0	130	0	0	4,092
Denbighshire	Rhyl South West	3,736	Rhuddlan and Flint	823	2,015	67	0	0	60	0	0	2,965
Denbighshire	Rhyl West	3,367	Rhuddlan and Flint	717	1,543	13	0	0	115	0	0	2,388
Denbighshire	St Asaph East	1,375	Conwy and Colwyn	532	316	31	0	0	32	0	0	911
Denbighshire	St Asaph West	1,265	Conwy and Colwyn	437	431	20	0	0	26	0	0	914
Denbighshire	Trefnant	1,496	Conwy and Colwyn	640	342	5	0	0	70	0	0	1,057
Denbighshire	Tremeirchion	1,313	Conwy and Colwyn	559	294	5	0	0	31	0	0	889
	Total	55,839		17,043	19,424	667	0	0	1,552	0	0	38,686

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

New seat: Conwy and Colwyn

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: Conwy and Colwyn
Conwy	Abergele Pensarn	1,936	Clwyd West	491	802	14	0	0	44	0	0	1,351
Conwy	Betws yn Rhos	1,663	Clwyd West	516	411	13	0	0	222	0	0	1,162
Conwy	Colwyn	3,623	Clwyd West	1,130	1,039	122	0	0	237	0	0	2,528
Conwy	Conwy	3,269	Aberconwy	951	1,126	42	0	0	204	0	0	2,323
Conwy	Craig-y-Don	2,748	Aberconwy	955	694	32	0	0	271	0	0	1,952
Conwy	Deganwy	3,154	Aberconwy	1,365	677	94	0	0	106	0	0	2,242
Conwy	Eirias	2,807	Clwyd West	853	824	118	0	0	164	0	0	1,959
Conwy	Gele	3,638	Clwyd West	1,269	931	34	0	0	304	0	0	2,538
Conwy	Glyn	3,412	Clwyd West	746	1,220	58	0	0	357	0	0	2,381
Conwy	Gogarth	3,088	Aberconwy	985	990	43	0	0	175	0	0	2,193
Conwy	Kinmel Bay	4,807	Clwyd West	1,832	1,347	43	0	0	133	0	0	3,355
Conwy	Llanddulas	1,208	Clwyd West	394	347	52	0	0	50	0	0	843
Conwy	Llandrillo yn Rhos	5,981	Clwyd West	2,374	1,411	69	0	0	320	0	0	4,174
Conwy	Llansanffraid	1,768	Aberconwy	651	478	45	0	0	83	0	0	1,257
Conwy	Llysfaen	2,160	Clwyd West	633	763	21	0	0	90	0	0	1,507
Conwy	Marl	3,109	Aberconwy	995	916	162	0	0	137	0	0	2,210
Conwy	Mochdre	1,520	Clwyd West	346	640	16	0	0	59	0	0	1,061
Conwy	Mostyn (Conwy)	2,811	Aberconwy	817	949	112	0	0	120	0	0	1,998
Conwy	Penrhyn	3,927	Aberconwy	1,572	1,001	65	0	0	152	0	0	2,790
Conwy	Pensarn	2,269	Aberconwy	633	671	33	0	0	275	0	0	1,612
Conwy	Pentre Mawr	2,777	Clwyd West	1,097	676	79	0	0	86	0	0	1,938
Conwy	Rhiw	5,238	Clwyd West	1,922	1,312	170	0	0	252	0	0	3,656
Conwy	Towyn	1,880	Clwyd West	780	472	16	0	0	45	0	0	1,313
Conwy	Tudno	4,036	Aberconwy	1,051	1,577	65	0	0	173	0	0	2,866
Denbighshire	Bodelwyddan	1,730	Vale of Clwyd	523	607	13	0	0	34	0	0	1,177
Denbighshire	St Asaph East	1,340	Vale of Clwyd	532	316	31	0	0	32	0	0	911
Denbighshire	St Asaph West	1,345	Vale of Clwyd	437	431	20	0	0	26	0	0	914
Denbighshire	Trefnant	1,556	Vale of Clwyd	640	342	5	0	0	70	0	0	1,057
Denbighshire	Tremeirchion	1,308	Vale of Clwyd	559	294	5	0	0	31	0	0	889
	Total	80,108		27,049	23,264	1,592	0	0	4,252	0	0	56,157

And these are the implied results for 2017 for the new seat of Conwy and Colwyn. 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:	David Jones (CON)
County/Area:	Clwyd (Wales)
Electorate:	80,108
Turnout:	70.1%

Conwy and Colwyn: New Boundaries 2018 Calculation

Conwy and Colwyn: Overview

Introduction