Owen Jones: The 1 per cent have an interest in demonising Ken Livingstone

Being on the left in public life means automatically inviting ridicule and venom. While only just over a fifth of eligible voters opted for the Conservatives at the last election, most of our media is firmly in the right-wing camp. Hacks and hit blogs pounce on every gaffe and any plausible example of a personal failing that clashes with left-wing beliefs: the right relish nothing more than exposing a socialist hypocrite.

Even a left-winger who is as close to unimpeachable as is humanly possible can expect a kicking, and Ken Livingstone is certainly not that. He dominated London politics before I was even born, giving him ample time to amass a wide array of enemies. His refusal to stick to the bland script of the modern politician wins support for independent-mindedness, but it has also caused offence. He was right to take a stand on massive tax avoidance by the wealthy at a time when chunks of the welfare state are being hacked away, and wrong not to order his accountant to avoid the many tax loopholes available for the well-to-do.

But it's clear that all-out war is now being waged against Ken. A display of human emotion at his campaign video launch led to a tirade of abuse from the obsessive, no-holds-barred right-wing Twittersphere, and mocking headlines in virtually every right-wing newspaper. As election day approaches, the chorus of abuse gets ever more shrill.

The Get Ken coalition includes right-wing hacks like Boris Johnson's Daily Telegraph colleague Andrew Gilligan, who is all but obsessed with Ken. He accuses Ken of having "links with Muslim extremists", arguing that it is "one of his most disturbing features", despite Gilligan himself being a former presenter on Iran's state-funded Press TV, which says all you need to know about Ken's most aggressive assailants.

And then there are Blairite ultras in Ken's own party, savaging him on websites such as Labour Uncut, who have never forgiven him for winning two major elections precisely by rejecting the New Labour formula. They attempt to kid themselves that Labour should have fielded a Blairite candidate, as though a politician with a record of total loyalty to all of New Labour's unpopular policies (such as the Iraq war – which Londoners overwhelmingly rejected) would fare well against a Tory Mayor adept at distancing himself from the Conservative brand.

Some of the smears thrown at Ken have veered between the ridiculous and the offensive. The award for chutzpah has to go to Tories who have accused him of homophobia. Ken may be straight, but he is Britain's equivalent of another local government campaigner for gay rights, 1970s US politician Harvey Milk.

When Ken made the case for gay rights as leader of the Greater London Council in the early 1980s, he was courageous indeed: at the time, two-thirds of the population thought homosexuality was wrong. The Tories went on to introduce Section 28, deliberately dipping into the deep well of homophobia. Surreal for a gay man like myself to imagine that, just a generation ago, we were widely regarded as perverts: it is a sea change in attitudes down to gay rights pioneers like Ken.

Contrast to Boris Johnson, who lauded Section 28 on the basis that "we don't want our children being taught some rubbish about homosexual marriage being the same as normal marriage", referred to "pulpit poofs" in the Church, and suggested that if two men could tie the knot, why not "three men and a dog"? Not that anyone is scrutinising such bigotry: it's just Boris being Boris, it's just his clownish manner. It's presumably for the same reasons that so few journalists mention his slights against black people: all that talk of "piccaninnies" with "watermelon smiles", or slamming the Macpherson Inquiry into the Stephen Lawrence case for "hysteria".

The same standards are certainly not applied to Ken. I never dismiss accusations of bigotry against Jews lightly. For most of the time I've been a Londoner, I've lived with two close friends who are the grandchildren of Holocaust survivors. The attempted extermination of the Jewish people – the culmination of two millennia of anti-Semitic persecution – remains a memory in the minds of people alive today.

It is extremely serious to cry anti-Semitism, not least if it prevents us from identifying the real thing. In Ken's case, the accusation was bandied around recently because – when asked about an alleged lack of Jewish support – he suggested that Jewish voters would divide in allegiance much as the rest of the electorate, with those who were wealthier opting for Boris. His opponents cynically misconstrued this as Ken reviving that old anti-Semitic caricature of the "wealthy Jew".

But, again, Ken was pushing the cause of anti-racism in the early 1980s with an enthusiasm that was dubbed "loony left". When Ken was Mayor, he sponsored the anti-racist music festival Rise – and, sure enough, when Boris entered City Hall, he stripped the event of its anti-racist message, and then abandoned sponsorship altogether. Not that Boris hasn't found his own persecuted minority to champion: the bankers, who he suggests are treated like "lepers". And he has his own crusade against injustice: namely the 50p tax, which only affected the top 1 per cent (including himself). If the wealthiest 1 per cent were to grow arms, legs, foppish hair and a manufactured bumbling demeanour, it would be Boris.

And then there are the issues which – in this dirty US-style campaign – have been driven off the agenda. We are in the midst of a housing crisis, which is why Ken's pledge to introduce a London Living Rent is so important. I'm about to move: scanning through Gumtree, I was horrified at how much rents have surged. Indeed, last year average rents soared by 12 per cent in the capital.

There is the promise to reverse soaring travel fares at a time when Londoners face the biggest drop in living standards since the 1920s. And then there's the promise to reinstate the Educational Maintenance Allowance for poor sixth-form kids.

If Ken loses, it will be a victory for a right-wing machine, its appetite whetted and ready to shred the next target. Ministers will undoubtedly respond as they did with the passing of the NHS privatisation Bill: pounding the Cabinet table with their fists. But while Millionaires' Row will have its champion back in City Hall, ordinary Londoners will be hit by ever-rising rents and fares.

The battle is on – between an imperfect Labour candidate, and the perfect embodiment of Britain's booming elite.