Ukip have never won a seat in the House of Commons, other than via defection, but the bookmakers and much of the commentariat make them narrow favourites to pull it off in Stoke-on-Trent Central, a Labour seat since 1935.

Are they right to do so? Labour’s difficulties have been enhanced as the Conservatives have pulled out of the race in all but name, in part to concentrate resources on the Copeland by-election on the same day, and also because local Conservatives want to focus their efforts on the nearby metro Mayor race in the West Midlands.

That well-reported story should make it easy for Paul Nuttall, the Ukip leader, who has made it his mission to take Labour seats in ex-industrial areas, and is the candidate in Stoke-on-Trent Central, to squeeze the Tory vote and overtake Labour, who had a 16 point lead over Ukip in second place, who were just 33 votes ahead of the Conservative Party in third.

But Ukip have a problem: finding their voters and getting them to the polling station. Ukip activists have always tended to prefer the high-profile aspects of campaigning – open top busses, handing out leaflets and balloons in town squares – over the hard and unglamorous work of finding their vote and getting it to the polling station.

In a symbol of that party’s organisational blues , they have been beaten in the postal vote in almost every seat they have contested. Indeed, in both Eastleigh and Heywood & Middleton, Ukip only lost because of postal votes. Although the party’s activists will occasionally blame postal votes on nefarious practices, the plain truth is that a strong postal vote is primarily the sign of a well-organised campaign. Look at Vote Leave: despite their strongest demographic being elderly voters without degrees, they managed to achieve big victories in the postal votes as well as on the day. There is not a political bias to postal votes – there is however an organisational bias. I'm reliably informed that there have been over 6,000 votes cast by post in Stoke - not very many elsewhere, but in the context of a seat that is bottom of the league as far as turnout, and given what we know about Ukip's inability to turn promises into postal votes, that attests to the likelihood they will fall flat.

One of the big struggles that field organisers in Vote Leave complained about was having to, as one put it, “house-train” Ukip activists in the unglamourous parts of campaigning. Some Conservatives in Vote Leave feared that the lessons instilled in Ukip activists in that contest would come back to haunt the Tories as they were used against them. Instead, that hasn’t happened – many of the Ukip activists who worked with Vote Leave have been either marginalised or have defected to the Conservative Party.

That means that Labour are increasingly confident that superior organisation will see off Ukip, as indeed are the Liberal Democrats, who are “having a punt” locally in the hopes of getting a good showing but have no expectations of winning the seat. But the Liberal challenge may well threaten Labour's hopes - they have selected a Kashmiri candidate and if they do well enough among the seat's British-Kashmiri population, which makes up 15 per cent of the seat, that could erode Labour's winning margin, particularly if they also peel away at the city's student population, too. Small wonder that Labour have decided that a visit from Jeremy Corbyn, focussed on those areas, and where he is still seen an asset, is worth the risk.