General election 2010: Lewis Baston’s tactical voting guide (5 May 2010)

Posted by lewis on May 5, 2010 in Guardian | Comments Off on General election 2010: Lewis Baston’s tactical voting guide (5 May 2010)

Our psephological expert offers the ultimate guide to deploying your vote to best advantage in a range of scenarios, based on the special eve-of-election Guardian/ICM poll

Part one: Conservative/Lib Dem marginals

1. The Lib Dems have a chance of gaining these marginal seats from the Conservatives, and tactical voting for the Liberal Democrats is strongly recommended if you want to avoid a Conservative majority:

2. The Lib Dems will need tactical votes to defend these seats from the Conservatives because they have been targeted for Tory gains, and in such seats a national swing may not be completely relied upon to keep the seat Lib Dem. These seats were within a 5% swing of the Conservatives in 2005.

3. You may want to vote tactically for a Lib Dem in these seats, which are targets from the Conservatives which Clegg’s party may be able to win with a big national swing or helpful local factors.

4. These are seats with Lib Dem incumbents who are safer than a 5% swing to the Conservatives but who may also merit a cautious tactical vote to protect them from any local or sudden surges.

Part two: Conservative/Labour marginals

1. These are Labour seats which the Conservatives would win on the basis of a 7% swing, as implied by the recent Ipsos Mori research in the marginals, and covering the 5.5% swing implied by the final ICM poll plus a 1.5% buffer in case the Conservatives are doing rather better in their target seats, or otherwise do better than expected. The “tactical power index” is a rough indicator of how powerful tactical voting might be in deciding the outcome in the seat. The figures in the chart are crude projections of the national poll changes. The index is the proportion of people who currently intend to vote Lib Dem who would be needed to vote tactically to save the seat for Labour (Labour having a one-point lead on the projection), taken away from 100 so that a high number indicates seats where tactical voting may be particularly effective.

2. Conservative seats where a tactical vote for Labour may produce change. This small selection is composed of Labour incumbents in seats where boundary changes have made the constituencies notionally Conservative on new boundaries, and a few cases of very small Conservative majorities where if there is a late swing to Labour there may be some chance of a gain. In each case, the Liberal Democrat vote starts too low to be in contention to win the seat:

Sittingbourne & Sheppey, Clwyd West, Hemel Hempstead, Kettering, Somerset North East (incumbent defends), Finchley & Golders Green, Shipley, Rochester & Strood, Wellingborough, Gravesham, Wirral West, Preseli Pembrokeshire, Thanet South (incumbent defends), Enfield North (incumbent defends), Staffordshire Moorlands (incumbent defends).

3. Labour seats vulnerable on a larger swing. Even on an average swing in the marginals of 7% to Conservative, there will be Labour seats that would succumb because the swing is a bit above average, and if Labour support falls as polling day approaches more may come into contention. For this reason, voters wishing to ensure the Conservatives do not gain an overall majority should support Labour in:

Renfrewshire East, Lancashire West, Vale of Clwyd, Telford, Coventry South, Warwickshire North, Newport West, Crewe & Nantwich, Leeds North East, Erewash, Dagenham & Rainham, Sherwood, Ellesmere Port & Neston, Luton North, Chorley, Norwich North, Gower, Birmingham Selly Oak, Bristol East, Wakefield, Blackpool South, Bassetlaw, Harrow West, Middlesbrough South & Cleveland East, Ealing North, Feltham & Heston, Plymouth Moor View, Blackburn, Delyn, Clwyd South, Slough and Birmingham Northfield.

This list comprises all those seats which would be Conservative gains from Labour on a 7-10% swing, and in which the Liberal Democrats do not come within 10% of the current winner when national poll figures are applied.

Part three: Other seats

There are a few constituencies where a candidate other than Labour or Lib Dem is best placed to keep the Conservatives out. In the marginal seats of Perth & North Perthshire and Angus, the SNP is narrowly ahead of the Tories. In Wyre Forest, Independent Richard Taylor (MP 2001-10) is the best-placed anti-Conservative candidate.

Part four: Debatable territories

Lib Dem supporters who are very keen to keep the Conservatives out should consider voting Labour in these constituencies, even if a movement in line with the current national polls would bring the Lib Dems into distant contention locally.

The Liberal Democrats may be best placed to defeat the Conservatives in these constituencies, despite being third in the 2005 election, and Labour supporters may wish to consider tactical votes in these cases.

The principal challenger to the Conservatives in two further semi-marginal seats (namely Dumfriesshire, Clydesdale & Tweeddale and Shrewsbury & Atcham) is not clear.

The following seats had Labour first in 2005 and the Conservatives in second, but on the basis of recent polls are three way contests:

Bristol North West, Colne Valley, Ealing Central & Acton, Northampton North.

The following seats had Labour first in 2005 and the Lib Dems second, but the Conservatives in a competitive third place:

Derby North, Edinburgh South, Hampstead & Kilburn, Watford.

Part five: And finally

The final list includes Labour seats ordered by how vulnerable they are. In most cases, a tactical Labour vote is advised. In some three-way marginals it is hard to offer advice which is not liable to be counterproductive.

Notes

Figures in charts are crude projections of results using the national vote changes implied by the final Guardian/ ICM poll which put the Conservatives on 36 (up 3 percentage points since 2005), Labour on 28 (down 8 percentage points) and Lib Dems on 26 (up 3 percentage points). These are applied to the standard Rallings & Thrasher estimates for the composition of the new constituencies in 2005.

For the avoidance of absurdities, no Labour constituency vote share is projected below 5 per cent; the crude figure is levelled up first from the 3 points otherwise accruing to ‘others’ and then if necessary from the Lib Dem gains.

http://www.guardian.co.uk/politics/2010/may/05/election-2010-tactical-voting-guide