I have never advised anyone to use the English libel laws. I spent years helping the campaign to reform them, and am proud of the liberalisation I and many, many others helped bring. I have to admit, though, our achievement was modest.

Libel in England remains sinister in intent – the defendant has to prove he or she was telling the truth – and oppressive in practice. Parliament and the asinine Leveson inquiry into the press failed to tackle the horrendous costs, and kept libel as the preserve of the rich and the reckless. You can risk spending £1 million before a case comes to court. Despite reform, libel courts remain the place oligarchs and charlatans go to suppress the truth.

Last night, however, I found myself advising the anti-fascist campaigner Maajid Nawaz to sue in the London courts. I even gave him the names of lawyers who would be happy to help. The attack he is facing is so grotesque, ferocious remedies seem the only response.

Nawaz’s enemy is not the usual user of the libel law: a Putin frontman or multinational. It is an organisation that ought to share Nawaz’s values, but because of the crisis in left-wing values does the dirty work of the misogynists, the racists, the homophobes, the censors, and the murderers it was founded to oppose. It does it with a straight face because, as I am sure you will have guessed, the fascism in question is not white but Islamic. And once that subject is raised all notions of universal human rights, and indeed basic moral and intellectual decency, are drowned in a sea of bad faith.

Nawaz is from Essex. He has fought and been beaten up by white British neo-Nazis. He fell in with Hizb ut-Tahrir while he was young. When he ended up in a torture chamber in an Egyptian jail, he abandoned Islamism for liberalism. Since then, he and his Quilliam Foundation have struggled against both the white far right and the Islamist far right. They have defended liberal Muslims and, indeed, all of us from lethal blasphemy taboos and the threat of terrorism. They respect freedom of speech, including the freedom of their enemies to speak. (When they asked me to introduce their report on online extremism, I was pleased to see them warning the state against the folly of trying to ban extremism rather than argue against it.) Quilliam and Nawaz support women’s rights and gay rights. They believe that there is no respectable reason why men and women with brown skins should not enjoy the same rights as men and women with white skins. They think they should try to stop young Muslims joining Islamic State, not just for the sake of the Yazidis they will take into sex slavery, or the civilians they will tyrannise and kill, but for the sake of the young Muslims themselves.

A significant faction on the left hates them for upholding the values they have forgotten, and will use any smear to denigrate them. As my secularist friend Faisal Saeed Al Mutar observed, when he, Nawaz and hundreds of others step forward and try to liberalise Muslim communities from within, they are attacked, ‘for being not Muslim enough, not Arab enough, not Pakistani enough, not filled with enough revenge and enough hatred’.

In the liberal orientalist world view the only ‘authentic’ Muslim is a barbarian. A battery of insults fires on any Muslim who says otherwise. They are ‘neo-conservatives,’ ‘native informants,’ and ‘Zionists’: they are as extreme as jihadists they oppose, or, let’s face it, worse.

In short, a section of the Western left has adopted the ideology of the Salafists, Khomeinists and Islamists. It supports their blasphemy codes, and apologias for murder. Not for white leftists, you understand, only for 'the other,' for we are in a culture where racist double standards abound. I have no doubt, for instance, that Alabama’s Southern Poverty Law Center (SPLC) would be appalled if white supremacists hacked to death writers on the New York Times for challenging racial prejudice, as Islamists hack Bangladeshi liberal writers to death for challenging theocratic prejudice.

What makes SPLC’s embrace of what it would in other circumstances correctly call fascist politics heart-breaking as well as contemptible is that it was once a great civil rights institution in the American south with a proud record of fighting the Ku Klux Klan.

It has turned McCarthyite now, and issued a blacklist of men and women it accuses of being ‘anti-Muslim extremists'. Pamela Geller, and a few other rabble rousers on the list are just that. As Amjad Khan shows, others are merely journalists and academics who have raised inconvenient facts conventional wisdom would rather ignore. Of course they could not leave alone Ayaan Hirsi Ali, who became an atheist and denounced the faith of her childhood, and is hated by a section of the white left for doing what they do all the time. That Hirsi Ali needs bodyguards to protect her from Islamist assassins in no way restrained our Alabama witch finders.

But the name that has jumped out at everyone is the Muslim reformer Maajid Nawaz. The text underneath oozes malice. The SPLC tries to make out that Nawaz’s stag night makes him an extremist. It misrepresents the work of his Quilliam Foundation so thoroughly I no longer recognised the organisation I knew. All these tricks and non-sequiturs, just so it can turn a liberal Muslim anti-extremist, into a reactionary 'anti-Muslim extremist'.

I asked the SPLC’s Mark Potok, ‘one of the country’s leading experts on the world of extremism,’ according to its website, if he was Muslim himself. ‘No.’ Was he happy, then, branding a liberal Muslim 'an anti-Muslim extremist?' Well, Potok said, the head of Scotland Yard’s Muslim Contact Unit had accused Nawaz of ‘demonising a whole range of groups that have made valuable contributions to counter-terrorism,’ and that was good enough for him.

I tried to explain that the then head of the Muslim Contact Unit was Bob Lambert, one of the most notorious agent provocateurs British policing has produced. He stole the identity of a dead boy and infiltrated left groups. Pretending to be one of them, he got an activist pregnant then vanished from his partner and child’s lives. He had a shadowy part in the ‘McLibel’ case, which led to two environmental activists being persecuted for years in the courts, and is under investigation for allegedly smearing the campaign for justice for the murdered black teenager Stephen Lawrence. There are reasonable grounds for suspecting that, when Lambert attacked Nawaz, he was trying to ingratiate himself with Islamists as he had tried to ingratiate himself with leftists.

Did Mark Potok, ‘one of the country’s leading experts on the world of extremism’ if you please, know he was relying on the word of a stool pigeon? ‘I don’t know the details.' Would the Southern Poverty Law Center, which is after all meant to defend the Stephen Lawrences of the world, reconsider its condemnation of Nawaz? With the braggart self-confidence of a liberal Donald Trump, Potok was not about to let facts change his mind. ‘No,’ he replied. Did Potok think he was putting Nawaz’s life in danger. 'No'

Of course he is. He and his colleagues have issued the white left’s first fatwa: a blacklist that could be a deathlist.

As Nawaz said,

“ It’s not as if there’s any shortage of Muslim extremists who want me dead. They exist in numbers so plenty that former jihadists have even taken to calling in to my live LBC radio show to confess to once having made plans to assassinate me. Europe has witnessed around 6,000 of our fellow Muslims leave to join ISIS. Here in Europe, amid jihadist assassinations and mass terror attacks planned with military precision, we truly are in the thick of it. Meanwhile, from the comforts of sweet Alabama comes this edict that liberal Muslims working to throw open a conversation around reforming Islam today are somehow to be deemed “anti-Muslim extremists.”

Do these jerks not think about the consequences of their rote-learned, pseudo-leftist bombast? Have they not heard that, across the world, lists circulate of ‘apostates’ along with invitations to the faithful to kill them when they can?

Maybe they have but do not care, and it will take drastic action to shake them out of their spiteful stupor. A court action could do it. If Nawaz sues, SPLC’s work in fighting the white far right will suffer grievously. But, as it is so eager to be on the wrong side in the fight against the religious far right, I think we could call it evens.