Why former Ukip voters could shape this election

We are now preparing carefully for election night. Here are a few notes that may or may not be helpful.

If you have been a bit confused from the start by talk of a Tory landslide, then it is best explained by one simple fact: the collapse of the Ukip vote since 2015.

Back then, Ukip got more than 3.8 million votes and a 12.6% share of all those ballots cast. But since the referendum - which arguably robbed the party of much of its raison d'être - the collapse has been spectacular (if not necessarily permanent).

In the last set of local elections, the party lost every one of its councillors running for re-election, some 145 in all.

Ukip appears to be somewhat strapped for cash and has thus taken the decision to field candidates in only around half the constituencies nationwide. It has said it will avoid targeting eurosceptic MPs where possible.

Theresa May's Conservatives could see a boost from former Ukip supporters. Credit: PA

This leaves a lot of Labour seats which had large Ukip votes at the last general election and large 'Leave' votes during the referendum looking particularly vulnerable. The trouble for the party is that there are a lot of them.

In fact, if you look at the 50 Labour seats with the smallest majorities, Ukip is not actually fielding candidates in 23 of them.

You would not, for example, normally expect a seat like Stoke-On-Trent South to be in play. It has historically been a safe Labour seat, but the majority here was only 2,539 last time and there were 8,298 people who voted Ukip.

This time around, Ukip is not fielding a candidate. The MP, Rob Flello, clearly has his work cut out.

That said, there is no guarantee these voters will necessarily switch to the Tories, if they turn out all.

Some left-wing candidates are also standing aside to boost other progressives. Credit: PA

Meanwhile, Theresa May is not having it entirely her own way. The Greens have also agreed to stand down in a number of seats to help other parties of the left.

In Brighton Kemptown, the Tory Simon Kirby only had a majority of 690 last time and yet 3,187 people voted for the Greens. This time around, they are not fielding a candidate there.

Similarly, Conservative Tania Mathias only has a majority of 2,017 in Twickenham, where Vince Cable is trying to win his former seat back. The Greens polled 2,453 votes last time and are not standing.

There could be a similar effect in Lewes and St Ives, but it is complicated by the fact that, in quite a number of seats, UKIP is not standing either (such as in Lewes, where the party got more than 5,000 votes last time).

In short then, you could really call this 'the Ukip election'. The key question appears to be how many Ukip voters in these marginal seats turn out on the day and how many of those that do decide, as most analysts have expected all along, to throw in their lot with the Tories.

If they do, Mrs May is going to have a pretty good night.

  • Tom Bradby is presenting ITV News Election 2017 Live: The Results from 9.55pm on Thursday. Watch on ITV and itv.com/news