"I'm the embodiment of every fascist's fantasy. I'm a Jew, a communist – and a heretical communist, a Trotskyist, at that. I don't fit anywhere. The only thing I happen not to be is homosexual."

My old friend Savvas Michael-Matsas – activist, internationally respected writer on philosophy and literature, general secretary of the Greek Revolutionary Workers' party (EEK), utopian thinker, fiery speaker and wild white-haired survivor of 17 courses of chemotherapy ("No compromise with death") – is on trial in Athens on Tuesday, 3 September, for "libelous defamation," "incitement to violence and civil discord", and "disturbing the public peace".

The suit against him has been brought by members and supporters of the neo-Nazi party, Golden Dawn; the background is a call to an anti-fascist protest issued by EEK in May 2009, which ended with the slogan: "The people don't forget, they hang fascists" (it's catchier in Greek). As Anny Paparousou, Savvas's lawyer, explained to me, this is effectively a prosecution of political speech – the first prosecution of an anti-fascist slogan in Europe. It's as if the National Front had sued the SWP for shouting "Smash fascism" – and been taken seriously. But with 18 seats in parliament, 13% in the polls and muscle-bound thugs on the streets, Golden Dawn makes the old NF look harmless and almost sweet.

Though Golden Dawn's suit was filed against a long list of individuals and organisations, only Savvas and Constantinos Moutzouris, former chancellor of the National Technical University of Athens, have so far been called to trial. Moutzouris's alleged offence is that he allowed the radical website Athens Indymedia to use the university's server; his prosecution may be seen as part of the government's campaign to shut down the "alternative space" in which leftists, anarchists and anti-austerity activists have thrived for many years. Savvas's trial fits that category, too: EEK is a meeting place for Marxist and anarchist currents, advocating, in Savvas's words, "not exit from the euro, which is a Talmudic discussion, but exit from the system". There's also a darker side: it's hard to avoid the conclusion that Savvas has been selected not only as a radical but as a Jew.

The progress of the trial thus far raises questions about whether, and if so to what extent, the authorities are colluding with the neo-Nazis. Several of Golden Dawn's members have serious charges pending but never seem to see the inside of a courtroom. Themis Skordeli, a signatory to this suit, was charged with stabbing an Afghan man in September 2011; her trial has been postponed eight times. The MP Ilias Panagiotaros, another of the complainants, owns a shop called Phalanga that sells street-fighting paraphernalia; he told the BBC last year that Greece is heading for civil war.

But picking out the Jew to be the first to walk the plank is sleazy beyond belief, a cheap sop to the fascist gallery. As one of the few Jewish public intellectuals in Greece, Savvas has long been targeted by neo-Nazi websites, with slogans like "Crush the Jewish worm" and claims that he can be found lurking under every stone, fomenting civil war among pure-blooded Greeks in order to establish a Judeo-Bolshevik state. He has also been accused of being both an agent of Iran and a fully paid-up member of the international Zionist conspiracy (in fact he's a fierce anti-Zionist), as well as having long hair (he does, despite the chemo and the rabbinical hat he bought in case he lost his locks).

The absurdity of all this doesn't make it less dangerous. "There is nothing reassuring about the repetition of a historical tragedy as farce," writes Savvas in his recent book, The Horror of a Parody: Three Talks About Golden Dawn. Article 192 of the Greek penal code, under which Savvas is charged, has been used twice against minority groups in the last 25 years; both times there were convictions. The rise of the far right in crisis-ridden Greece has both fed on and fuelled a blood-and-belonging nationalism and hatred of the other for which antisemitism is the original historical pattern. "Kill the Jew you carry inside you and is your negative self, incapable of giving your life meaning through a higher ideal," counselled Golden Dawn's first declaration of ideological principles. "Then, fight the Jew around you."

The Greek government has made common cause with these people in its desperate effort to drive home the neoliberal agenda of its creditors and protect Greece's own corrupt elites. The admittedly violent rhetoric of parts of the Greek left is equated with the widespread physical violence of the extreme right, which is cosseted and supported in its crusade against immigrants, leftists, homosexuals, misfits of all kinds. There is to be no room in the new order for anything counter, original, spare, strange.

I first met Savvas years ago at a conference celebrating the centenary of the Greek surrealist poet and visionary Andreas Embeirikos. We spoke about the writer's relationship to the work of Herman Melville, especially Moby-Dick, and Savvas still puts me in mind of the white whale: a force of nature sounding to great depths, bent on a single quixotic quest, not for revenge but for liberation – no less vital for being always out of reach. The black-shirted skinheads of Golden Dawn, driven by fear and hate, are the Ahabs of this world. They must not be allowed to win.