What effect will Nigel Farage’s Brexit Party have on the Tory vote?

The Brexit Party’s decision to stand against the Tories at the general election has been widely interpreted as bad news for Boris Johnson.

Nigel Farage’s party was reportedly considering standing aside in some seats to give the prime minister a clear run to avoid “splitting the Leave vote”. He effectively announced on Friday that it would not unless a number of essentially impossible conditions were met.

But the situation may not be as straightforward as “splitting the Leave vote”, and there are some interesting caveats worth looking at.

It’s true that Brexit Party voters lean heavily towards the Tories: 78 per cent prefer Johnson as prime minister and just 1 per cent prefer Jeremy Corbyn, YouGov found in August.

But prime ministerial preference is not the same as voting for a party, and evidence from the last time Faragism did well at a general election suggests that the effect is more complicated than the two parties simply drawing from the same pool of voters.

In 2015, Ukip secured 12.6 per cent of the vote – and yet the Tories managed to win a majority, their only one since 1992.

Analysis of seats at the 2017 election, too, suggests that the Tories actually did slightly better in seats where Ukip stood than in ones where they decided to stand down.

One plausible reason for this is voters who are socially conservative and prefer Faragism to Labour – but will never vote Tory. Given the choice, these voters would vote Ukip or the Brexit Party, but in their absence, a proportion will end up voting Labour.

If this is indeed what is happening it will be relevant in the 2019 election because the main places the Tories want to pick up seats are in Leave-leaning areas in the north and Midlands. The historic damage Tory governments did to those parts of the country in living memory means that you can find plenty of antipathy to the Tories in them.

The splitting the vote hypothesis also has other problems. Behavioural studies on tactical voting tend to find that split votes happen when voters have a strong preference for their first choice over the second, and believe their first choice has a chance of winning.

But Johnson has gone to great lengths to negate the appeal of the Brexit Party over the Tories for dogmatic Leavers, by emphasising that he alone has the power to “get Brexit done”. Leave voters are also perfectly capable of looking at past results and understanding where they can most effectively direct their votes. A brief dive into Brexiteer social media shows an active debate in Leaver circles about who to vote for and plenty of planned tactical voting.

Rather than directly splitting the vote, the decision of the Brexit Party to stand could count against the Conservatives in one indirect, but important way. Nigel Farage now appears set to spend the election campaign on television doing his best to toxify the prime minister’s Brexit deal with Leave voters, by branding it a sell-out.

This could do more damage than specific local effects on the ground. As much as driving votes for Farage’s own party, it is likely to demoralise Leavers thinking of voting Tory in all constituencies and could suppress their turnout. Farage’s main power has always been as a media personality, and never as the marshall of ground forces capable of winning constituencies in British general elections.

All the effects described above will have some effect on the final result. The question is which one will be the strongest and prevail: we can’t really know that until the votes have been cast. But there’s good reason to be wary of simplistic first readings.