The Electoral Calculus postbag has contained quite a few emails recently from Liberal Democrats worried that our predictions are not showing them doing well enough in some seats.
The seats in question are often those where the Liberal Democrats came second to the Conservatives in 2019 and which are on Labour's published list of non battleground seats. Lib Dems suggest that they are the natural 'anti-Conservative' candidate in those seats, and that Labour or Green party supporters will therefore vote Lib Dem there to defeat the Tories.
Our correspondents express surprise that our predictions often show Labour as the challenger to the Conservatives rather than the Liberal Democrats, and suggest that these predictions are less than accurate.
Now it's true that tactical voting may be an important factor at the next election, and that Labour, Lib Dem and Green supporters are particularly likely to vote tactically. You can read our poll on Tactical Voting from last autumn.
Electoral Calculus is not in the business of encouraging or discouraging tactical voting for or against any party. Our aim is to accurately predict voter behaviour, by looking at the evidence of opinion polling. So what does the evidence say?
In our recent MRP poll, we have a large sample of over 15,000 voters which lets us look at this question in a bit more detail, and double-check the MRP predictions.
Seats in England and Wales which are either Strong (dark orange) or Medium (light orange) for the Liberal Democrats
To do this, we split the 632 new GB parliamentary seats into three groups, depending on the likely strength of the Lib Dem vote in each seat. The three groups are:
It's interesting to note that all of the 'Medium' group of seats appeared on Labour's list of 'non battleground' seats.
We can use our poll to estimate the parties' vote shares separately for each group of seats. These vote shares are based on straightforward quota-weighted polling analysis, and do not use any of the more complex MRP methods. This gives us a simple independent cross-check.
The projected vote shares for all of the main parties in these three groups are:
| Party | Strong | Medium | Weak |
|---|---|---|---|
| CON | 26% | 28% | 21% |
| LAB | 20% | 30% | 47% |
| LIB | 34% | 21% | 6% |
| Reform | 10% | 13% | 12% |
| Green | 7% | 8% | 8% |
| SNP/Plaid | 2% | 0% | 5% |
| Other | 1% | 1% | 1% |
| Num seats | 63 | 44 | 518 |
| Sample size | 1,381 | 859 | 12,909 |
As can be seen, the Liberal Democrats are well ahead of the two biggest parties in terms of vote share in the 'Strong' group. This suggests that centre-left voters in these seats believe that the Lib Dems are the main challenger to the Conservatives and have chosen to vote Lib Dem. It also suggests that the Lib Dems are likely win many of these seats. This is consistent with our MRP poll, which predicts the Lib Dems will win 50 of these 63 seats.
But in the 'Medium' group, Labour are in first place on 30%, just ahead of the Conservatives, who are well ahead of the Liberal Democrats on 21%. This indicates that Labour is the likely challenger to the Conservatives in many of these seats, according to the voters. We note that voters are giving more support to Labour than the Lib Dems in these seats, even though they are on Labour's list of non-battleground seats. This is also consistent with our MRP poll, which predicts Labour will win 19 of these seats, with the Conservatives winning 16 and the Lib Dems just three seats.
In the 'Weak' group, Labour is very clearly ahead of the Conservatives, and the Liberal Democrats are in fifth place behind Reform UK and the Green party. The MRP model does not predict any Lib Dem seat gains in this group.
One possibility is that the Lib Dems are expecting that voters in the 'Medium' group of seats will vote tactically once the next general election gets closer. At the moment many voters are not very engaged with either politics or the new seat boundaries. This may change nearer the election as voters start to focus on the political choices before them and on the tactical outlook in their own seat. But that is speculation at the moment. On the basis of asking voters in these seats now, they tell us that they prefer Labour to the Liberal Democrats, and our predictions reflect that.
Of course, as the election draws closer, voters' attitudes to the main parties can change and, as that happens, all of our seat-by-seat predictions will update in real time.
The lists of the 'Strong' and 'Medium' seats are given below.
Bath, Bermondsey and Old Southwark, Bicester and Woodstock, Brecon Radnor and Cwm Tawe, Caithness Sutherland and Easter Ross, Cambridge, Cambridgeshire South, Carshalton and Wallington, Cheadle, Cheltenham, Chesham and Amersham, Chippenham, Devon North, Devon South, Didcot and Wantage, Dorking and Horley, Dorset West, Eastbourne, Eastleigh, Edinburgh West, Ely and East Cambridgeshire, Epsom and Ewell, Esher and Walton, Farnham and Bordon, Fife North East, Finchley and Golders Green, Frome and East Somerset, Glastonbury and Somerton, Godalming and Ash, Guildford, Hampstead and Highgate, Harpenden and Berkhamsted, Harrogate and Knaresborough, Hazel Grove, Henley and Thame, Honiton and Sidmouth, Kingston and Surbiton, Lewes, Mid Dunbartonshire, Newbury, Norfolk North, Orkney and Shetland, Oxford West and Abingdon, Richmond Park, Romsey and Southampton North, Sheffield Hallam, Shropshire North, St Albans, St Ives, St Neots and Mid Cambridgeshire, Sussex Mid, Sutton and Cheam, Taunton and Wellington, Thornbury and Yate, Tunbridge Wells, Twickenham, Wells and Mendip Hills, Westmorland and Lonsdale, Wimbledon, Winchester, Woking, Wokingham, Yeovil
Arundel and South Downs, Buckinghamshire Mid, Chelmsford, Chichester, Christchurch, Cornwall North, Cotswolds North, Cotswolds South, Dorset Mid and Poole North, Dorset North, East Grinstead and Uckfield, Essex North West, Fareham and Waterlooville, Hamble Valley, Hampshire East, Hampshire North East, Hampshire North West, Herefordshire North, Horsham, Maidenhead, Melksham and Devizes, New Forest West, Newton Abbot, Reigate, Runnymede and Weybridge, Rutland and Stamford, Salisbury, Sevenoaks, Shropshire South, Stratford-on-Avon, Surrey East, Surrey Heath, Sussex Weald, Tewkesbury, Tiverton and Minehead, Torbay, Witney, Worcestershire West