Opinion Polls

UK General Elections #10A – The Cursed Ratios of British Politics

December 7, 2025 By Nigel Marriott

I used to be a commodity trader in the 1990s. This wasn’t my day job, which was to forecast supply & demand, but I had the statistical skills to develop automated trading strategies for the traders I worked with. These were either based on moving averages of futures prices (known as technical trading) or buy/sell signals based on the underlying supply & demand picture (known as fundamental trading). I don’t trade commodities now but I’ve applied the stats skills I learned then to many time series since including those for elections and voting intentions.

Another trading strategy I could have used but didn’t was Chartism. I vividly remember the training course I did on this and coming away gobsmacked. How on earth were people being allowed to buy and sell millions using nothing more than astrology, spiritualism, numerology and other superstitions?! I immediately swore of from Chartism and have managed to stay away from it until this year. I hope you understand why it’s taken me many months to build up the courage to publish two articles where I use chartist superstitions instead of statistics to interpret long term trends in the vote shares of the major parties in the UK.

For this article, I explain why my charts show the Cursed Ratios of British voters are 52 : 26 : 13 : 6.5. For my next article, I will have you fearing for my sanity…

UK General Elections #9 – The 40-55 Channel

July 4, 2025 By Nigel Marriott

Voting intentions in Britain were remarkably stable for the first half of 2025. The last time the polls were this stable was 10 years ago in the run up to the 2015 General Election.

What’s that I hear you say? Have I not noticed the surge in Reform’s vote share from 20% to 30%? I have but I’m focusing on the 40-55 Channel which has been the defining feature of voting intentions for nearly all of the last 15 years. Everything I see in 2025 tells me the 40-55 Channel will continue to define British politics all the way through to the next election by 2029. Perhaps I better explain what I’m talking about.

UK General Elections #8 – How accurate are voting intention polls? – updated with GE2024

August 4, 2024 By Nigel Marriott

After their 2nd best ever performance in the 2019 UK General Election, the UK polling industry flipped in the 2024 UK General Election to their 2nd worst ever performance after 1992. 6 of the last 9 elections have seen at least one party experience a major polling error. It would appear the move to web polling and lower barriers of entry has led to poorer quality polls.

UK General Elections #7 – How accurate are voting intention polls? – Revised

June 8, 2024 By Nigel Marriott

Voting intention polls in the UK are accurate after all!

For years, I’ve observed that UK polls on average underestimate the Conservative vote and overestimate Labour’s vote. When I converted poll data into forecasts of seats won, I had to first estimate how much polling error there would be. So what’s changed? It turns out I was comparing polls to the wrong statistic, namely national vote share. The correct comparator is in fact average vote share per seat.

UK General Election 2024 #1 – Going beyond the swing

February 18, 2024 By Nigel Marriott

Labour is on course for a crushing landslide later this year… or are they? Many parallels with 1997 are being drawn at the moment but it’s too early to be making detailed forecasts. Instead, I want to lay the foundations for my election forecast later this year by looking at what 100 years of UK electoral history is telling me. I tell this story by assigning probabilities to 10 specific outcomes of interest and finish by explaining why 2024 is more likely to be a repeat of 2001 than 1997.

I remind you I was deemed the most accurate forecaster of the 2019 general election. This article is the first in what I hope will be a series of articles which lead me to hold on to that accolade!

UK General Elections #5 – How accurate are voting intention polls? – updated with GE19

December 29, 2019 By Nigel Marriott

After 3 general elections with severe polling errors, the UK opinion pollsters redeemed themselves in the 2019 UK General Election with their most accurate performance since 1955. I base this statement on data provided by Mark Pack who has systematically recorded every opinion poll published since 1945. The challenge now for the industry is to maintain this level of performance for the next election which may be easier said than done given that 5 out of the last 8 elections have experienced a major polling error.

UK General Election 2019 Voting Intention – Final Polls

December 12, 2019 By Nigel Marriott

Today, the UK votes in its 3rd general election in less than 5 years. After serious polling errors in the last 3 general elections, it is understandable that everyone is taking the latest figures with a lot of salt. As it stands today, the polls are telling us that the Conservatives recovered their 2017 standing but Labour are still behind their 2017 performance.

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UK Opinion Poll Tracker #16 – December 2019

December 5, 2019 By Nigel Marriott

Next Thursday, the UK will vote in its 3rd general election in less than 5 years. After serious polling errors in the last 3 general elections, it is understandable that everyone is taking the latest figures with a lot of salt. As it stands today, the polls are telling us that the Conservatives have more or less recovered their 2017 standing but Labour are still behind their 2017 performance.

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UK Opinion Poll Tracker #15 – November 2019

November 29, 2019 By Nigel Marriott

In two weeks time, the UK will vote in its 3rd general election in less than 5 years. After serious polling errors in the last 3 general elections, it is understandable that everyone is taking the latest figures with a lot of salt. As it stands today, the polls are telling us that the Conservatives have more or less recovered their 2017 standing but Labour is still a long way from repeating their 2017 performance.

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Stats Training Materials – Sampling & Surveys

July 17, 2019 By Nigel Marriott

The core expertise that Statisticians offer to the world is drawing conclusions from small samples. Therefore, knowing how to design surveys, estimate the right sample size, decide on the right way to ask the question or measure a property are all essential skills for any statistical thinker. The skills you need to be competent in Sampling & Surveys are best captured by my Survey Wheel.