Greens tipped for narrow win in WECA metro mayor election (2025)

A statistician has the political parties almost neck and neck

The West of England mayoral election is a five-way marginal that could be one of the closest polling-day battles in British history, with the Greens set to claim a tight victory, an expert has predicted.

Independent statistician Nigel Marriott, from Bath, has crunched the numbers from voting patterns at previous local and national elections in the region and concluded that all five political parties’ candidates have a chance of being the next metro mayor from May.

But the Conservatives are least likely to win, while the one independent is expected to trail a distant sixth.

His forecast, which is here, has the Greens in the lead on 24 per cent of the vote, which would be an incredibly low figure to win an election, such is the even split.

Labour and Reform are each predicted to receive 20 per cent, the Lib Dems 19 per cent, the Tories 12 per cent and the independent taking five per cent.

Mr Marriott said: “This is shaping up to be one of the most unpredictable elections I’ve ever seen.”

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He has used four different statistical models, given each a weighting depending on how accurate he thinks they will be, and then calculated the weighted average for each party to give the overall percentages.

Two of the models actually have Labour in front, with the Greens and Reform on top in the other two.

Mr Marriott said: “On average, the Greens come first with 24 per cent but Labour, Lib Dems and Reform are all on or around 20 per cent which is nothing in the grand scheme of things.

“What I will say is the Green and Lib Dem estimates are fairly stable across the four models unlike the Labour, Conservative and Reform parties which vary a lot between the models.

“The Conservatives are behind in all models but I am happy to call this a five-way marginal with the Greens most likely to win and Conservatives least likely.”

The metro mayor is the elected head of the West of England Combined Authority (Weca), comprising Bristol, South Gloucestershire and Bath & North East Somerset councils.

Mr Marriott said: “I am forever struck by Weca’s political diversity.”

He said in the nine local, national and EU elections from 2010 to 2024, five different parties topped the polls – the Conservatives and Labour both finishing first on three occasions, with the Lib Dems, UKIP and the Greens receiving the most votes once.

The statistician made the most accurate prediction of the 2019 general election and also correctly forecast the Greens would win the most seats in last year’s Bristol City Council ’s local elections but fall short of a majority.

In 2021 he expected the Tories to retain the role of West of England mayor but the race was won by Labour’s Dan Norris, who was arrested on suspicion of rape and child sex offences earlier this month.

Mr Marriott said he now realised he made an error in his calculations for the Weca mayoral election four years ago and had adjusted his analysis.

Speaking of his 2025 prediction, he said: “What could go wrong with such a forecast? A lot.”

He said 12 per cent for the Conservatives was much more likely to be an underestimate than an overestimate because the collapse of the party’s vote at last year’s general election was driven in part by supporters staying at home, and a good local candidate could still get them out this year.

Mr Marriott said: “Polls published in the last few days look like they are showing a bounce for the Lib Dems.

“At the moment, they are not included in my latest polls for 2025.

“When I update my forecast towards the end of April, this bounce, if sustained, will feed through and give the Lib Dems a boost.”

He said polls showed the party’s increase in support was at the expense of Labour, which could also suffer as a local reaction to Mr Norris’s arrest, so the forecast 20 per cent could turn out to be lower.

Mr Marriott said: “Reform is the hardest party to forecast.

“They didn’t stand in 2021 and so have no obvious base to build on.

“On the other hand, they are polling comfortably at 25 per cent in the national polls and the local elections across England is a real opportunity to show they are now a political force.

“They’ve chosen a candidate with name recognition and depending how he campaigns, he must have a chance in a five-way marginal.

“Whilst one of my models has them winning, my model did not predict Reform directly.

“Instead, it predicted a combined Reform plus Independent and then split that total 80:20.

“That split is a pure finger in the air assumption and if the independent candidate does better than I expect, Reform won’t be winning.

“Lastly, we come to the Greens who are the favourite according to my models at the moment.

“Until now, they have always been in opposition.

“But last year, they took minority control of Bristol City Council.

“That means Bristol voters have had a year of experiencing life under Green rule.

“Has that made them more or less favourable?

“I have no intelligence on the ground personally but I think as a general rule in these times, incumbent ruling parties find it hard to sustain support.

“Therefore there is a risk my models are overestimating the Greens.”

The six candidates in the election on Thursday, May 1, are:

• Arron Banks (Reform UK)
• Helen Godwin (Labour)
• Oli Henman (Liberal Democrat)
• Mary Page (Green)
• Ian Scott (Independent)
• Steve Smith (Conservative)