UKIP’s non-candidacy in three South Yorkshire seats seems, on the surface, likely to benefit the Conservatives.
The logic is simple enough. Theresa May has bet the farm on the 52% who voted Leave in last year’s referendum. If she can unite the pro-Brexit vote behind a single Tory candidate, Labour incumbents will be in peril.
Take Don Valley, for instance, which Caroline Flint has held since 1997. The seat voted heavily for Leave, and Conservative Councillor Nick Allen has told South Yorkshire Briefing his party intends to campaign there.
In 2015, UKIP and the Tories combined took 48.8% of the vote in Don Valley. Ms Flint won 46.2%. In Doncaster Central, the combined Tory and UKIP vote would overcome Labour’s Rosie Winterton based on current national polling.
However, the electoral calculations are not as simple as that.
Labour have strong incumbents. Ms Flint, Ms Winterton, and John Healey in Wentworth and Dearne all increased their majorities on a poor election night for their party in 2015. There are obvious dangers in applying a national swing to South Yorkshire.
Secondly, it is fantasy to think that 100% of former UKIP voters are going to support the Conservatives in South Yorkshire. Many of them voted Labour before 2015. The memory of Thatcherism is strong, though Mrs May is skilfully attempting to jettison her party label. Labour performed well in Doncaster amid otherwise dreadful local election results last week. Some UKIP voters will not vote at all.
Third, a defection of UKIP voters to the Conservatives has already been priced into polling figures. According to the latest YouGov poll, some 53% of people who voted UKIP in 2015 are intending to vote for the Tories in 2017.
In Wentworth and Dearne, SYB is projecting (not predicting) a Conservative vote share of 25.8% based on national polls. But it would be mistaken to add UKIP’s 24.9% from 2015 to create a majority, because that level of UKIP support no longer exists.
The number of UKIP voters to redistribute is therefore uncertain. Still, SYB is making a tentative projection based on the share UKIP would receive if they were in the race.
In Don Valley, according to the Electoral Calculus polling average – caveats apply – Ms Flint would have a majority of 5.9% over the Conservatives, with UKIP third on 16.6%.
If the UKIP vote is divided between Labour and Conservative candidates, the Tory challenger Aaron Bell would need around 70% of UKIP votes to unseat Ms Flint. That is plausible.
In Doncaster Central, however, our projection is that Conservative candidate Tom Hunt would need to scoop up around 90% of UKIP voters.
And in Wentworth and Dearne, SYB is projecting a Labour majority which no amount of tactical voting could overturn.
It is Ms Flint, therefore, who probably has most to fear from the lack of a UKIP candidate. The Conservatives could challenge Mr Healey or Ms Winterton too. But UKIP’s withdrawal is not likely to help those efforts by very much.