General election forecast

Monmouthshire

Predicted winner: Labour with 29.6% of the vote, a 0.6pp margin over Conservative.

wales · wales

Predicted vote share

How the model expects this constituency to vote

Labour

29.6% +29.6pp

Conservative

29.1% +29.1pp

Reform UK

20.3% +9.6pp

Green Party

9.0% +4.4pp

Lib Dem

4.3% -0.2pp

Restore

3.3% +3.3pp

Plaid Cymru

2.6% +2.6pp

Independent

0.8% -0.1pp

True & Fair Party

0.5% -0.0pp

SNP

0.3% +0.3pp

Heritage Party

0.2% -0.0pp

Other

0.0% 0.0pp

Coloured number is the swing from the 2024 general election result.

Sitting MP

Catherine Fookes

Party: Labour Party
Tenure: 2.1 years (since 2024-07-04)
Status: standing again

What happened on 4 July 2024

Candidate	Party	Votes	Share
Catherine Fookes	Labour Party	21,010	41.3%
David Davies	Conservative and Unionist Party	17,672	34.8%
Max Windsor-Peplow	Reform UK	5,438	10.7%
Ian Chandler	Green Party	2,357	4.6%
Bill Powell	Lib Dem	2,279	4.5%
Ioan Bellin	Plaid Cymru - The Party of Wales	1,273	2.5%
Owen Lewis	Independent	457	0.9%
June Davies	True & Fair Party	255	0.5%

Source: Returning officer declaration

How accurate is the model here?

Our 2024 backtest for this constituency

We replayed the same model architecture against the 4 July 2024 general election using only the data a forecaster running the model in May 2024 would have known. Here's what it would have predicted for Monmouthshire, and what actually happened.

✗ Winner missed , predicted Conservative, actual Labour. Major-party MAE: 4.69pp, the average gap between our predicted vote share and the actual share, per major party.

Predicted

Labour

31.4%

Conservative

31.7%

Reform UK

14.5%

Green Party

6.2%

Lib Dem

9.5%

Plaid Cymru

3.0%

Independent

1.2%

Other

0.8%

Workers Party

0.8%

Actual on 4 July 2024

Labour

41.3% -10.0pp

Conservative

34.8% -3.1pp

Reform UK

10.7% +3.8pp

Green Party

4.6% +1.6pp

Lib Dem

4.5% +5.0pp

Plaid Cymru

2.5% +0.5pp

Independent

0.9% +0.3pp

Other

0.0% +0.8pp

Workers Party

0.0% +0.8pp

Positive gap = we predicted that party would win more share than they did. See the full GE backtest across all 650 seats for the model's national accuracy.

How this forecast was built

GE2024 Baseline. Actual GE2024 result in Monmouthshire
National Swing (Strong Transition Model). Multiplicative bounded swing, losers shed in proportion to local share, gainers absorb pro-rata national gain. Replaces additive UNS.
BES MRP Prior. Baseline blended with BES Wave 1-30 wales prior at weight 5%
Age-structure adjustment. 65+ 25.9% → Reform +0.40pp, Con +0.20pp (BES-dampened)
Normalise. Shares scaled to 100%

Read the full general election methodology →