It had been obvious from at least the date of the last general election that the honourable Douglas Carswell MP was doing his utmost to damage UKIP.

When I said this few believed me. But the preview of Owen Bennett’s The Brexit Club book has revealed the truth. I was right.

I was astonished to read a piece in the Times last May which appeared under Carswell’s name but was actually written by Tory MEP Daniel Hannan, in which he said that UKIP must not campaign on “the idea that EU membership is synonymous with immigration”. No doubt Carswell will deny this authorship but telling outright untruths comes easily to him.

Neither of these men believed that immigration should be an issue in the referendum as they saw it as an issue that put voters off. Perhaps in their narrow and rarified world it does. But winning elections, especially this referendum, meant that immigration had to be front and centre of the campaign.

Rather like the Cambridge ring of Soviet spies, they convinced themselves that by damaging UKIP and me they were doing the right thing.

They chose to believe that Nigel Farage was toxic to voters. Indeed Mr. Carswell told me that I should play no role in the referendum campaign.

They may have smart academic qualifications but they are not street wise. And clearly cannot read polls.

The only people to whom myself and the immigration issue is toxic are to the well-heeled committed Remain voters, the sort of people who live in the Hannan and Carswell world.

Our own extensive polling last summer led to a clear conclusion: if we could make immigration synonymous with EU membership we would win.

There were some commentators who noticed that Carswell was in a strange position. Lord Finkelstein in the Times could see that joining UKIP under my leadership and to condemn our key policies did not make sense.

As the Vote Leave operation slowly began to take shape it was clear that it was not much more than a Tory organisation with a dash of Labour for show.

Despite the overwhelming support of UKIP peers, MEPs and the party’s NEC to back the Grassroots Out bid for designation, Carswell supported his old Tory friends.

As the campaign began in earnest he did his best to split UKIP and to render it a weak voice in the campaign. He wanted us to be subsumed by Vote Leave.

The Vote Leave spin operation was convinced they could silence me with their daily negative briefings. I am pleased to say they did not and that the people’s army of UKIP were on the streets and happy to help any organisation.

In the end 90 per cent of those who believed that open door immigration was bad for the economy voted for Brexit.

Many of them were traditionally non-voters. The voice of Farage and UKIP had reached an audience that the posh boys could never touch.

So I could conclude that the totally dishonest Carswell campaign had failed in its objective to damage UKIP. Sadly in one important area he had achieved success.

When the Clacton by-election was in progress Neil and Christine Hamilton announced they were to appear. For the last few years Neil has lobbied relentlessly to get back into elected politics. Wisely, UKIP’s governing body rejected his candidacy in 2014 and 2015. Indeed Carswell himself was horrified by the prospect of being photographed with them in Clacton and told me so.

The Welsh Assembly elections took place this year in the middle of the referendum campaign and he saw his opportunity. Knowing that Hamilton’s record would attract negative publicity and seriously upset nearly all of UKIP’s donors, he helped to persuade the NEC that Hamilton should be a candidate.

He told the room that Hamilton would be an asset to the party. And that they had been very welcome in Clacton.

Sadly the governing body hearing this and having been lobbied endlessly by Hamilton were not bright enough to see through Carswell’s intentions.

So the man who has campaigned on a new, radical, cleaned up form of politics has put back into public office one of the most discredited political figures of modern times.

The honourable Douglas Carswell indeed.

The Brexit Club, the new book by Owen Bennett, is available now on Amazon