Zac Goldsmith came in for a fair amount of criticism yesterday after writing a piece in the Mail on Sunday that, among other things, pointed out that Sadiq Khan criticised Labour’s decision to suspend Ken Livingstone in 2006 when he compared a Jewish Evening Standard journalist to a Nazi concentration camp guard. Reviewing the papers on Marr, Owen Jones called it 'another example' of a 'poisonous' and 'disgraceful' campaign that had tried to brand Khan as an extremist simply because he’s a Muslim. He called it 'an attempt to tap into anti-Muslim prejudice' and urged Conservatives to tackle Islamophobia as vigorously as his own party is tackling anti-Semitism.

But is the Conservative mayoral candidate’s campaign, which is being run by Crosby Textor, guilty of Islamophobia? The accusation isn’t that Goldsmith or anyone linked to the campaign has said anything overtly Islamophobic. Rather, they’re been accused of 'dog whistle' politics – of trying to play on people’s anxieties about Islamism and terrorism by posing questions about Khan’s links to Islamist extremists.

I know from experience that it’s extremely difficult to defend yourself when accused of these things. You can point out that nothing you’ve said or done is, in your view, racist or Islamophobic, but your accuser will simply respond that it’s not for you, as a privileged white male, to define what is and isn’t an example of the sin in question. Indeed, any attempt to do so, with the implication that you are a better judge of the matter than a member of a victim group, will itself be denounced as an example of racism. What your accuser is effectively saying – and this applies to the critics of Goldsmith’s campaign – is that they can see into your heart and they know you’re guilty. Any attempt to deny it is just one more piece of evidence to be used against you.

But any reasonable person would want to know the answers to some key questions before making up their minds about this, such as whether Goldsmith has any form in this area – has he been accused of Islamophobia before? – and whether Khan actually does have links with Islamist extremists. They might also wonder whether Goldsmith’s opponents, like Owen Jones, are disinterested observers or have something to gain by branding his campaign 'poisonous' and 'disgraceful'.

To my knowledge, Goldsmith has never been accused of anything like this before. He has a good relationship with the Kingston Muslim Association in his constituency and has held surgeries in the local mosque. But, of course, his accusers have an answer for this. According to them, Goldsmith is a decent man brought low by his desire to win an election. The fact that there’s no evidence of any Islamophobia prior to the campaign makes him even more of a villain. He has sacrificed his principles for political power, etc, etc.

What about Khan? There’s no question that he’s made all the right noises during the campaign, condemning extremism and being one of the first senior Labour figures to call for Livingstone’s suspension last week. And to give him credit, he has earned the lifelong enmity of various radical Islamists by supporting gay marriage.

But you don’t have to go back very far in Khan’s past to find links with some pretty unsavoury characters. Some of these associations date back to his time as a director of Liberty and a human rights lawyer – trying to get the UK to lift its ban on the American Nation of Islam leader Louis Farrakhan, who has described Jews as 'blood-suckers' and called Hitler 'a very great man', and speaking at the same conference as Sajeel Abu Ibrahim, a member of the now proscribed Islamist organisation that trained the 7/7 bomber Mohammad Sidique Khan. But other instances are less easily explained away by his professional commitments.

For instance, in 2004 he appeared on a platform with five Islamic extremists at a conference in London organised by Al-Aqsa, a group that has published works by the notorious Holocaust denier Paul Eisen. He was billed not as a director of Liberty or human rights lawyer, but as a Labour parliamentary candidate.

In the same year, Khan was the chair of the Muslim Council of Britain’s legal affairs committee and was involved in defending the Muslim scholar Dr Yusuf Al-Qaradawi, whom the MCB described as 'a voice of reason and understanding'. At the time, the MCB issued a press release blaming the 'smear campaign' against Qaradawi on 'the Zionist lobby'. Khan himself gave evidence to the House of Commons Home Affairs Select Committee in which he said 'there is a consensus among Islamic scholars that Mr Al-Qaradawi is not the extremist that he is painted as being'.

So who is this Muslim scholar, who was warmly welcomed to London in 2004 by Ken Livingstone? Among other things, he’s the author of a book called The Lawful and Prohibited in Islam in which he justifies wife beating and discusses whether homosexuals shours be killed. Most notoriously, he condones 'martyrdom operations', i.e. suicide bombings, against Israeli civilians, which he describes as 'God’s justice': 'Allah Almighty is just; through his infinite wisdom he has given the weak a weapon the strong do not have and that is their ability to turn their bodies into bombs as Palestinians do.' In spite of holding these views, Qaradawi is not an 'extremist' in Khan’s eyes.

In 2006, by which time he’d been elected to Parliament, Khan was one of the signatories of a letter to the Guardian that blamed terrorist incidents, such as 7/7, on British foreign policy, particularly Britain’s support for Israel. 'It is our view that current British government policy risks putting civilians at increased risk both in the UK and abroad,' it said.

So 10 years ago Khan held similar views about 7/7 to those of Ken Livingstone, who sparked outrage last November when he said on Question Time that Tony Blair’s foreign policy was to blame for the terrorist attack that left 52 Londoners dead.

Khan has positioned himself as being on Labour’s 'soft left' and he was Ed Miliband’s campaign manager during the 2010 leadership election, but views such as these align him more closely with Jeremy Corbyn, whom he nominated during the 2015 leadership election. As you’d expect, he has done his utmost to distance himself from Corbyn since securing the mayoral nomination, but he wouldn’t have won it without the support of Corbyn’s allies, including Len McCluskey, and he’s relying on the campaign muscle of Momentum – the grassroots Corbynite organisation – to get out the vote for him later this week.

It’s also worth pointing out that those who’ve been the most vociferous in their condemnation of Goldsmith’s campaign as 'Islamophobic' are Corbyn’s closest allies – people like Owen Jones and Diane Abbott. They have a vested interest in seeing Khan win the mayoral election because if he doesn’t, Corbyn will surely be toast. As it is, the local election results are set to be Labour’s worst in opposition since 1982 and the party could lose control in Wales and be beaten into third place in Scotland. Winning in London is the only thing that can save Corbyn’s skin.

I, too, have been accused of 'dog whistle' politics for asking questions about Khan’s past – after I tweeted a link to Goldsmith’s article yesterday, Jones denounced me as 'one of the most unpleasant individuals I have ever had the misfortune to encounter'. But it’s not as if I’ve confined myself to just criticising Khan for being wobbly on this issue. When it comes to pointing out links between senior Labour politicians and Islamic extremists, I’m an equal opportunities offender.

The truth is, it’s not Islamophobic to point out Khan’s dubious associations, any more than it would be ageist to point out Jeremy Corbyn’s. Indeed, one of Khan’s most persuasive critics is Atma Singh, Ken Livingstone’s advisor on Asian affairs from 2001-07. The only people guilty of being 'poisonous' and 'disgraceful' in this mayoral race are those making these baseless accusations – and let’s not forget the same charge was made against critics of Lutfur Rahman.

I thought twice before writing this piece because I know it will bring another flurry of unpleasant accusations from the hard left. But it’s perfectly legitimate to scrutinise those who would wield power over us, even if those individuals happen to belong to a minority group. Khan shouldn’t be given a free pass just because he’s a Muslim, any more than his religion should be a reason not to vote for him. Many of the views he’s expressed in the past and the people he’s associated with suggest he belongs on the regressive left, alongside Corbyn, Abbott and Livingstone. Indeed, until last Friday he was happy for Livingstone to join him on the campaign trail and was proud of the former mayor’s endorsement. Pointing that out isn’t blowing a dog whistle and it isn’t Islamophobic. It’s a fact that should be taken into account by London’s voters, along with many other facts about Sadiq Khan, when they go to the polls on Thursday.