At the Political Book Awards at the beginning of the year, Lord Ashcroft told the audience that:

“I hope that next year with Isabel Oakeshott that we may have one of the books up there for ‘Political Book of the Year’. As most of you know we are writing the obit… Ah sorry David, the biography.”

The Tory peer who saved the Conservatives from bankruptcy during the late 1990s and early 2000s bankrolled David Cameron's assault on Downing Street in 2010. Now, he’s the author of Call Me Dave, a biography of Cameron, currently being serialised in the Mail.

Day One kicked off with the allegation that David Cameron had, as part of an initiation into the upper-class drinking society Piers Gaveston, put his penis into a dead pig’s mouth. (Day Two brings with it allegations that Cameron, while prime minister, attended a party in which illegal drugs were “openly” passed around. What is Lord Ashcroft thinking? Is he trying to bring down Cameron or the government?

The short answer is no. The polling disaster – covered before the fact extensively in the New Statesman – did not come from an entirely clear blue sky. Labour’s weak performances in local and European elections – and the continuing unpopularity of Ed Miliband all hinted that the polls might be overstating Labour support. Privately, pollsters at several companies were nervous about their own numbers. Staffers at ComRes in particular were nervous about the numbers, as were some members of YouGov and Populus. “I wouldn’t trust it, myself,” one pollster told me a month before the result.

But Ashcroft wasn’t one of them. He was confident in his new constituency polling, even though pollsters for both Labour and the Conservatives were sceptical about their efficiency. (The difficulty of polling a constituency is getting enough demographic information to have an accurate sample.) He thought – like Anthony Seldon, the author of a less sensational account of Cameron's years at Number 10 – that his book would come out after Cameron had been defeated, and Miliband had been installed as prime minister.

The hope wasn’t to bring down Cameron but to humilate him in retirement. Ashcroft was bruised by a failure to consult him about big decisions during the 2010 campaign and the offer of what he saw as a derisory role as a Foreign Office whip after the election.

“If Cameron had lost, he’d have been smashed up by his own party,” Seldon told me in a forthcoming interview for the New Statesman. Ashcroft’s hope was that these allegations would come out when Cameron had none of the infrastructure of Downing Street or CCHQ to respond to the stories, while some on the right of the Conservative party, who have assisted with the story, hoped to bury Cameron’s rebrand of the Tory party along with him. But as for bringing down Cameron? Frankly, there is no chance of that. The allegations around Piggate will be widely believed but unless it emerges that he has embezzling government money to pay a pork farm to bring a pig’s head to Downing Street at weekends it will remain a subject for mockery, not serious political pressure. (The sideshow over the pig’s head will also ensure that most people ignore the question of whether or not Cameron lied about when he knew of Ashcroft’s tax arrangements.)

What’s really happening is that Ashcroft, like Seldon, thought he was “writing about a corpse”. Instead, he faces a prime minister who is very much alive. It may well be that Ashcroft himself comes out worst from the clash.