There is only one reason why Zac Goldsmith and his campaign keep commenting on, and feeding stories to the press on, Sadiq Khan’s links with radical Islamic preachers. It’s because his campaign advisor – Lynton Crosby, has convinced him it will work. As for me, it is giving me a very good reason TO vote for Khan, but as you may have noticed, I am not normal, and the normal voter may just feel that Khan’s links to Islamism are too important and poll too well to miss. In Crosby-speak, everything else is a bit “barnacle-y”.

To understand this, former Cameron speechwriter Clare Foges tells a story about working for Crosby’s ultimately successful General Election campaign last May. She had written “long term economic plan” for the thousandth time when Crosby sat her down for a lesson in barnacle scraping. This was related to his famed strategy of “scraping the barnacles off the boat”: which means to pare the message down to a couple of well-polling lines to be repeated endlessly.

“He presented a chart showing both the issues about which the public cared most or least (high or low importance) and the issues on which Conservatives were seen as strongest or weakest (high or low approval). The NHS was high importance but low approval, so was to be avoided wherever possible; don’t fight on the fronts where you’re bound to lose. The economy and jobs ranked as high importance and high approval so were drums to be banged like Animal in the Muppets on speed. Pretty much everything else, from education to the environment, was a barnacle on the boat, to be sloughed off so that you are left with a simple, clear, repetitive, boring campaign that will drill your message into the public consciousness whether they like it or not.”

Goldsmith (no relation to me by the way), has been advised that Khan’s links to radical Islamists are high importance and high approval. He and his campaign are currently banging that drum as hard and fast as they can. Never mind that Khan worked as a human rights lawyer. Never mind that he also worked for Liberty, the civil liberties pressure group, never mind then that it was his job to uphold the hard earned rights we all have in this country to be treated fairly, never mind the fact that Khan has made a point of travelling to diverse communities and trying to persuade them to get involved in civil society, the fact that he merely stood on the same stage as someone with questionable views is enough to brand him as potentially dangerous.

Khan is a man who has had death threats for voting in favour of gay marriage, a man who campaigned to keep his local pub in Tooting open, a man who has said he regrets his party’s “unacceptably anti-Jewish” image. If he is too radical or extremist to be London Mayor, then could any Muslim be Mayor.

As the journalist Mehdi Hasan points out: “The irony is that Khan’s election to the mayoralty would be a massive victory in the battle against extremism and terrorism. His arrival in City Hall would be a stark rebuttal of Isis-inspired claims that the west is at war with Islam, that democracy and Islam cannot be reconciled, that Muslims have no future in Europe. It is difficult to overstate the huge symbolism and historic significance of a Khan win on 5 May. To have a Muslim elected mayor of London, with a bigger personal democratic mandate than any other politician in Europe bar the presidents of France and Portugal, would strike a significant blow against the simplistic narratives of Islamophobes and Islamists alike.”

What I take away from this is firstly the sad truth that it may still matter to some Londoners that Khan is a Muslim, and not in a good way, otherwise Crosby wouldn’t have told Goldsmith to use it. I also take away that Goldsmith is concerned about losing, and doesn’t have a positive story to tell.

Forget the EU REMAIN campaign’s ‘Project Fear’. This is a much sadder Project Fear, because it tells us a lot about what Zac Goldsmith has to offer London. I have to ask Goldsmith to question whether he actually wants the victory that attacking Khan’s religious background will give him? We have nothing to fear from Sadiq Khan, and if this is all Goldsmith’s got then Khan has certainly got my vote.