When Jörg Haider, the leader of Austria's far-right Freedom Party, joined the country's coalition government in 2000, the response from the rest of the European Union was swift. Every other member state agreed to introduce diplomatic sanctions against Austria. Our then foreign secretary, Robin Cook, expressed "deep distaste" at Haider's rise to power.
Fourteen years later, will Foreign Secretary William Hague express "deep distaste" if, as the polls suggest, Narendra Modi of the Bharatiya Janata Party (BJP) is declared prime minister of nuclear-armed India after 12 May? Will the EU have the guts to downgrade diplomatic ties with the world's biggest democracy?
Of course not, even though Modi makes the late Haider look like a muesli-eating, sandal-wearing liberal. If we're going to make analogies with European leaders, Modi, the chief minister of Gujarat since 2001, is more in the mould of Milosevic than Haider.
Modi, who is 63, is a card-carrying member of the far-right, Hindu nationalist Rashtriya Swayamsevak Sangh (RSS); he started volunteering for the group at the age of eight and became a full-time pracharak (propagandist) for it at the age of 20. "The RSS is a secretive, militaristic, masculine cult; a distinct Indian form of fascism that was directly inspired by Italian Fascist youth movements," Professor Chetan Bhatt, director of the Centre for the Study of Human Rights at the LSE, tells me. "Its founders greatly admired Hitler and Mussolini." In Modi's Gujarat, Adolf Hitler is glorified in secondary-school textbooks.
As chief minister of Gujarat, Modi turned a blind eye to - indeed, many would argue, even incited - a horrific wave of violence against Gujarat's Muslim-minority population in February 2002, after a fire on a train which killed 59 passengers, most of them Hindu pilgrims, and which Modi blamed on "terrorists". It is estimated that as many as 2,000 people were killed in the anti-Muslim pogroms that followed, and tens of thousands lost their homes.
A chilling report published by Human Rights Watch (HRW) in April 2002 documented how the orgy of killing, burning, raping and looting had been "actively supported by state government officials". It spoke of how a pregnant Muslim teenager had had her womb "cut open with a sharp weapon... the unborn baby was taken out and both mother and the child were burnt dead". Several witnesses were told by police: "We have no orders to save you."
As a result, India's Supreme Court described Modi as a "modern-day Nero", fiddling while Gujarat burned. The National Human Rights Commission concluded that "there was a comprehensive failure on the part of the state government to control the persistent violation of the rights to life... and dignity of the people of the state". The bloodstained buck stopped with the BJP chief minister.
Modi has never apologised for the violence, nor has he expressed remorse. On the contrary, he explained away the killings as springing from "the natural and justified anger of the people"; dismissed relief camps for displaced Muslims as "baby-making factories"; and (I kid you not) compared his own sadness over the massacres with that of a driver who runs over a puppy.
A Modi-led India won't be safe for the country's 176 million Muslims - or 25 million Christians. Since the election campaign began, one of his hard-right allies has said the chief minister's opponents would have to leave India and move to Pakistan once he was elected PM. Another suggested that Muslims could be prevented from buying property in Hindu-dominated areas.
Yet David Cameron's government has been reaching out to Modi, the leader of one of India's most business-friendly states. In October 2012, the UK lifted its travel ban on Modi and our high commissioner in India held his first meeting with the chief minister - even though three British citizens were murdered in the Gujarat violence.
It isn't just members of the Conservative-led coalition rushing to embrace the darling of the Hindu nationalist right. In August 2013, Barry Gardiner, the shadow environment minister, invited Modi to visit parliament in his own capacity as chair of Labour Friends of India - or what Bhatt refers to as "Labour Friends of the RSS". Disgracefully, Gardiner has praised Modi as "a hugely important figure", defended his role in the 2002 killings and, in a contemptible attempt to minimise the awfulness of the events, compared them to the London riots of 2011.
As someone of Indian origin, I'm ashamed that the homeland of my parents is on the verge of making an authoritarian populist, with Muslim blood on his hands, the next head of government. Remember: India is a secular democracy where many Muslims have thrived. The current vice-president and foreign minister are both Muslims.
As a British citizen, I am also ashamed that my government is willing to cosy up to standard-bearers of religious fascism - as long, it seems, as they aren't Muslim. The realpolitik excuse will not wash. "While the UK and European governments are obliged to engage with other heads of government," Bhatt says, "there is considerable political and diplomatic flexibility how that engagement takes place."
Putin, Castro, Chávez, Ahmadinejad, Milosevic... it is so easy to denounce our "official" enemies. Yet, inexcusably, we give a pass to the blood-drenched Modi.
Mehdi Hasan is the political director of the Huffington Post UK and also a contributing writer for the New Statesman and this column is crossposted here.Suggest a correction