On Tuesday night I was at a dinner in central London where the Shia sect I belong to has a mosque, with a beautiful roof garden and social space. People of all backgrounds had gathered to break bread and mark the end of another long day of Ramadan fasting. Mayor Sadiq Khan, the guest of honour, spoke stirringly about our wonderful mixed city and the enemies of tolerance – Islamist terrorists and white extreme nationalists. He looked tired and genuinely troubled about those who carry and spread the malignancies.

Though the two ideological camps oppose and leech off each other, their philosophies, declarations and methods are interchangeable. They seek to destabilise and distort human relationships and stable governance. They hate mutuality between diverse citizens, they hate multiracial living and loving, they hate cultural and biological miscegenation, they hate all those who do not see the world in black and white, but in colours and shades.

Examine the profiles and you find the same sense of grievance and paranoia, a manic need for status and 'clean' identities, a demonstrable susceptibility to indoctrination. If a reality show was invented to put Islamists and members of the English Defence League in the same isolated country house, after some rows and brawls, they would emerge as blood brothers.

So it is no surprise that after vehicles were weaponised by Isis-inspired terrorists in London, Darren Osborne, a white bloke from Cardiff who apparently often fulminated about Muslims, drove to Finsbury Park and mowed down worshippers from the local mosque. The press and the broadcast media did not react with the practised shock horror they produce when bad Muslims do terrible things. They sought to minimise the significance of the incident. The alleged attacker's close relatives denied he is racist and talked about his chaotic life, as if that gave him permission to do what he did. You never get such empathetic narratives for Muslim terrorists. The difference is stark and concerning.

Finsbury Park Mosque vigil
A bus with a religious quote on it passes a crowd as a vigil is held outside Finsbury Park Mosque Dan Kitwood/Getty Images

Tommy Robinson, aka Stephen Christopher Yaxley-Lennon, the attention-seeking white, hard-right nationalist (who truly, madly, deeply abhors all Muslims) sounded off about the 'Muslim problem' after the Finsbury attack. That got him invited onto key TV programmes so he could say the unsayable, damn the Quran as a "violent and cursed book", get presenters a bit hot and bothered and create a sordid drama out of a crisis.

Most politicians, legal professionals and media commentators still think that neo-fascism is a fringe activity, a bit like modern day witches or pagans. How very wrong they are.

Radical British nationalists are getting more active, more unafraid and more popular. Almost a quarter of all referrals to government deradicalisation programmes are now of men, women and children who belong to hard-right groups. Parts of Wales and England are now hives of anti-foreigner animosity. Police monitoring figures show racist abuse and violence has gone up alarmingly. Muslims, at present, get the worst of this. Young white children are being groomed to become xenophobes and end up physically assaulting children who have dark skins or are from minority cultures and faiths. These youngsters are just as vulnerable as those in Muslim enclaves who get turned by manipulative operators. They both need safeguarding before it's too late.

In Germany, there is more awareness of the dangers posed by the hard right and more concerted political action to prevent history from repeating itself. The National Democratic Party (NDP) is reputedly anti-Semitic, anti-democratic, anti-constitutional and openly xenophobic. Last year, as a result of effective campaigning, the party failed to win a single parliamentary seat. Angela Merkel and others spoke up to defend Germany from creeping fascism. Here decent citizens of all backgrounds have rallied around victims, but have you heard a single leader from our main political parties speak often and with conviction on white terrorism?

I have had death threats in the last five years, just because I am brown-skinned, female and in the public eye. Some who were out to get me were violent Muslims who do not care for my liberal values and lifestyle. Most, however, have been hard-right whites. Sometimes the police had to be called. The house had to be made more secure, I learnt what to look out for before driving off and to be less candid about my movements on twitter.

After Islamist attacks take place, more vile people think they have the right to warn and terrorise me. The Brexit debates also incited these sick people. The bad old days, when I first moved to Britain, seem now to be kinder and safer.

The Finsbury attack proved white extremism is as lethal as Islamist extremism. Our leaders must now confront that truth and danger. If they don't they are passive colluders who deserve damnation.