David Cameron and the Tories’ electoral hopes are about to take a long walk on Clacton’s short pier. A poll in the Mail on Sunday today has Ukip on 64% and the Tories on 20%, a lead that suggests this contest is over before the writ has even been moved.

So, Ukip are going to get their first MP. This means that the fracture on the right of British politics is a lot closer to becoming permanent, handing Labour the kind of inherent electoral advantage that the Tories enjoyed in the 1980s. This morning, the next election is Ed Miliband’s to lose.

One of the striking things about the poll is that it reveals that not even Boris can save the Tories in Clacton. Cameron had hoped that his ‘star striker’ could get him out of this hole. As one Cameron loyalist tells me, ‘Their first reaction was to get Boris to do it’. But word quickly came back from the Mayor’s camp that this wasn’t a goer; that Clacton was simply too far from London for the Mayor to stand there.

Number 10 sources say that the approaches to Boris were more ‘jokey banter’ than anything else. But with whatever humour the suggestion was made, Cameron was in earnest. In this battle, the Tories could really do with their most popular champion.

Boris, though, won’t be standing and it looks like whoever the Tory candidate is won’t stand much of a chance against the Carswell juggernaut. Ukip will soon have the foothold at Westminster that they have long craved. With this, it will become that much easier for them to keep their momentum going and far harder for the Tories to squeeze their support.

Cameron’s chances of staying in Number 10 post 2015 are significantly smaller now than they were 72 hours ago.

Tags: 2015 general election, Clacton by-election, Coalition, Conservatives, David Cameron, Douglas Carswell, Ed Miliband, Europe, Nigel Farage, Tories, UK politics