EVERY year on December 5th and 6th, tens of thousands of Dutch people paint their faces black, don Renaissance-style jerkins and pantaloons, and assume the persona of Zwarte Piet ("Black Pete"). The comical character plays a vital part in the celebration of the feast day of St Nicholas, known as Sinterklaas, which overshadows Christmas as the most important children’s holiday. According to a custom standardised in the late 1800s, Sinterklaas arrives on a steamboat from Spain, accompanied by a team of his black-faced servants, who distribute presents and ginger biscuits to good children while threatening to scoop up naughty ones in a sack and carry them back to Spain to pick oranges.

With his fantastical role and antique costume, Zwarte Piet seems disconnected from modern racial stereotypes. He made it through the Netherlands’ politically correct 1990s without raising many eyebrows. Yet in recent years Dutch citizens of Caribbean ancestry have begun protesting the portrayal of St Nicholas’s sidekick as a racist caricature. In the increasingly polarised political climate in the Netherlands, the custom was a tinderbox waiting for a match. In October the debate exploded, polarising cultural life and dragging in celebrities, politicians, and even the UN.

The man who lit the tinderbox is Quinsy Gario, a Curaçao-born Dutch performance artist, who began protesting in 2011 when he attended a Sinterklaas parade wearing a T-shirt reading “Zwarte Piet is racism” and was arrested. In early October Mr Gario appeared on the Netherlands’ most popular television talk-show to make his case again. The following week, the mayor of Amsterdam met with dozens of residents who had submitted a complaint asking that Zwarte Piet be removed from the city’s Sinterklaas parade.

Most white Dutch reacted angrily to accusations that the tradition is racist. On social media, many repeated a long-standing claim that Zwarte Piet just appears black because of soot from the chimneys he climbs down to deliver presents. The right-leaning Telegraaf, the country’s largest newspaper, ran articles claiming anti-Piet voices were troublemakers who did not represent black people in the Netherlands. A “Pietition” page on Facebook backing Zwarte Piet gathered over 2m likes within days, a staggering response in a country of 17m.

Many Dutch who have come out against Zwarte Piet have been hounded by the traditionalists. One group in the country’s north who had planned to paint themselves as multicoloured “rainbow-Piets” had to give up after receiving death threats. Anouk, the Dutch representative at this year’s Eurovision contest, was attacked with racial epithets for her opposition to the custom. When a Jamaican researcher for a UN cultural panel said she thought Zwarte Piet was racist, she was overwhelmed with racially offensive e-mails. Geert Wilders, the anti-immigrant populist whose Party for Freedom is currently on top of the Dutch polls, tweeted that he would rather eliminate the UN than Zwarte Piet. A pro-Piet protest in The Hague turned sour when a dark-skinned woman was surrounded by an angry mob and had to be rescued by police.

Mark Rutte, the prime minister from the centre-right Liberal Party, commented simply that “Black Pete is black”. The head of his centre-left coalition partners, Diederik Samsom, belittled the argument as an affair for people with too much time on their hands. But while the symbolism of a children’s holiday may be of limited consequence, the contemptible racial attitudes it has exposed are not. This month’s conflict has changed Zwarte Piet. For many, even if a year ago he was not a symbol of Dutch racism, he is now.